With editor's notes (in italics) that incorporate recent taxonomy changes etc.
First published in the: Cactus and Succulent Journal (U.S.), Vol. 67 (1995), pp 195-247. as: Mastering the Art of Growing Mesembs.
Only the text reproduced here with the kind permission of Steven Hammer.
Steven Hammer is not only the master in the delicate art of cultivating the mesembryanthema, he is also a master with words. This article will vastly enhance the ability of growers to successfully maintain this amazing group of plants. Yet it does far more than that; it is helping to bridge cultures right around this beleaguered planet of ours. I especially wish to acknowledge the hard work of Lindsey Deaves in scanning and proof reading the original article.
D. J. (Didge) Rowe,
Mesembs, as the more succulent members of Aizoaceae are familiarly known, are currently in a favorable horticultural position. A great deal of interesting material is freely available, new discoveries continuously enliven our greenhouses, and enthusiastic collectors around the world have acquired the necessary skills to grow the plants well. However, there are many more succulent-lovers who would like to grow mesembs, but they are discouraged by multiple and contradictory theories regarding watering and resting schedules.
Radically conflicting precepts published over the last sixty years—particularly those concerned with the question of “resting” times—have collectively caused much unhappiness, confusion, and plant loss. In an effort to clear up the confusion I present here some general rules and observations, followed by comments on each of the genera most likely to excite interest and trauma. That much of my advice contradicts previous authors is not because I enjoy controversy, but rather because my experiments made over the last thirty years have shown that much published and widely parroted dogma simply isn't true.
Some examples: short-day species (monilarias, mitrophyllums, and oophytums) do not grow better if sown in winter; faucaria seed does not take a year to ripen; lithops are not always self-sterile; conophytums dislike summer droughts and they do not grow in winter; deep pots and their consequence, deep waterings, are neither necessary nor desirable for lithops or most other genera; daily watering is not fatal; and so forth.
While testing these and many other mesembroideries, I have found techniques that do work well and have suggested them to many other growers worldwide. In turn, these growers and their green guinea pigs have helped me. And yet advice is a funny thing: people ask for it freely but they rarely seem to follow it to the letter. Perhaps we all like to make our own mistakes, the best-learned if most painful of lessons.
Much public advice has been too parochial. What worked magnificently for Ed Storms, whose plants experienced sunny winters and blistering Texan summers, does not always work for others; Ed himself was well aware of this (Storms, 1986). His principal technique, especially with regard to lithops, was based on the avoidance of summer watering, a practice unnecessary elsewhere. Schwantes' techniques (Schwantes, 1954) were strongly conditioned by the gloom of Hamburg and by an often counterproductive cautiousness regarding new introductions.
Tischer's seemingly prescient ideas (expounded in Labarre, 1931) have held up very well, but they are not widely known now; I adapt some of them here. Jacobsen's ideas, widely followed via the ubiquity of his handbooks, are a farrago of northern and southern practices, with some fantastic idealism thrown in. His advice about Muiria hortenseae (water it only between July and September!) must have doomed many plants of this fat water-loving species to terminal dehydration.
My own advice suffers from the limitations of my experience, of course—some readers will wonder at my alkalinity-obsession—but having worked in two hemispheres and in several different climates, I have some basis for comparisons. I must admit that many genera were easier to manage in California; but not everyone can live within quake-range of the Pacific. Besides, I have been astounded by the ease with which my European friends can cultivate and propagate many of the smaller mesembs, especially conophytums. I almost begin to see abundant ultraviolet not as a friend but as an enemy, the limiting spoiler; and yet ultraviolet, or a reaction to its presence, is responsible for the colorations—the stark whites and strong purples—that we find so attractive in the mesembs.
Horticulture as practiced among mesembophiles is an art of minute personal idiosyncrasies, not an exact science; it demands Jove and observation, not formulae. Many growers, like closet tipplers, tend to fool themselves about their actual practices: they will say that they “never” water a certain plant in summer, but in fact they give the plant frequent mists, or their spouse takes secret weekly pity on it.
Not only are growers individual, plants are too. Gordon Rowley grows the normally shade loving Conophytum stephanii subsp. abductum right next to C. burgeri on an upper shelf so bright that the nearby glottiphyllums turn brick red. All these plants flourish, and I cannot explain how they (and Gordon) manage it. A musical analogy: the hand positions of Horowitz and Gould were peculiar, wrong, impossible, yet these pianists achieved miraculous sounds. Gould preferred not to analyze his own unorthodoxies, and indeed he found analysis paralyzing.
I should acknowledge straight away that different growers can obtain good results from techniques which seem quite contradictory. But at least most good growers have an internally consistent technique, a learned pattern of acute response.(1) Technique gives one a feeling of confidence; it even gives one the confidence to risk failure.
The requirements of most mesembs are actually simple and unambiguous once one learns to see their signals. When visitors ask me how I know what a plant wants at a given time, I try to make them see what I see—and this article has the same goal—but of course the real secret lies in long observation of the plants. Over time, they will teach one exactly what they need. Attempting to put their lessons into words requires many pages, hence the length of this article. I am grateful to Myron Kimnach for allowing me such ample space, and to John Trager, whose photographs allow plants to tell their own stories. [not included in this text file]
1 The difference between technique, good luck, and genius is that genius cannot be taught or imitated, while technique is learned, repeatable, and reliable; mere luck defies repetition. I once germinated a pot full of happy saphesias and cannot recall how I did it.
Mesembs have an annual cycle which varies little from year to year. The sequence is genetically fixed; it does not go haywire when plants are brought from the southern to the northern hemisphere, though such plants are temporarily confused. Captive mesembs have no memory of, or loyalty to, the month in which they or their parents flowered. They are loyal only to day-length and should match the growing pattern of their forebears, but at half a year's distance. In a given horticultural ambience, many plants even flower on the same date year after year and go dormant at the same point.
Mesembs oscillate between rapid growth and relative torpor, generally flowering toward the end of active growth. Conophytums are a remarkable exception, though one could argue that even here the flowers are terminal and that any subsequent vegetative expansion merely amounts to a squirrelish topping-up of leaves already fully formed.
Nietzsche said: Sleeping is no mean art; for its sake one must stay awake all day! During their sleepily inactive periods mesembs tend to seem dull, losing some of their leaves and acquiring strange colors; for example, after passing through an unnervingly yellowish phase, most sphaeroids will shrink-wrap themselves in dead white. Others will have a brief erythematous phase which fades after a few weeks. With many of the leafier mesembs, torpor is obvious: the plants show no new growth at the axils. This is common in Astridia, Bijlia, Cerochlamys, Ruschianthus, and Titanopsis (among others), and it may last throughout the summer.
At the beginning of the active cycle (shorter, cooler days for some genera, warmer, longer days for others—see under each genus, below) the plants will acquire or reveal richer green colors. They usually make their intentions obvious. When new leaves are visible at the axils they will normally grow very quickly, followed perhaps by a second and third decussate pair. The next pair will bear bracts or their simulacrums and, ultimately, flowers and fruits.
Some plants are so shocked by summer heat that they take longer than normal to emerge, like the reluctant groundhog in reverse. With these one must be especially patient; they may wake up only after mid-winter, when the days are already growing longer. I suspect that this very late emergence is being directed by the already-formed new bodies, which have minds of their own.
Though the growing sequence cannot be substantially altered, one can manipulate the timing of its onset by artful watering and also delay the period of flowering and dormancy. There is some practical value to such practices; it makes it possible to synchronize normally disparate flowering times. Where summers are mild, one can take advantage of early growth. Delayed dormancy lengthens the growing season, thus increasing the potential for ampler division of many “stemless” species. But at most one will gain a few weeks in either direction.
Some mesembs are like fleas: they breed and die rapidly. Others live the lives of mice given to fond but careless children; one can expect a year of activity followed by a slow or rapid fade-out. But the majority of mesembs are (very) perennial, and the super-succulent sphaeroids often outlive their caretakers. They are forgiving and self-renewing; unlike cacti, they absorb and erase our mistakes.
The oldest conophytum in cultivation is now ca. 180 years old (its age at the time of introduction to England is unknown); the oldest lithops was collected ca. 1918 and is still thriving. The Stomatium agninum var. integrifolium met with in a few English collections apparently stems from the very plant known to Salm-Dyck. Many other methuselahs must exist, but like those ancient Armenians who live on sunflower seeds, no one knows quite when they were born. Senility in compact mesembs arrives via the stems and roots, not via the leaf-pairs or “bodies,” which are completely renewed at least annually (what an inspiration for the plastic surgeon!).
Most leaves do not live for more than two years, after which they shrivel to a tough brown leather or flake away like dandruff. Stems, however, are almost always persistent, gradually increasing in length and thickness while decreasing in efficiency. Eventually they become too thick and woody; they are vulnerable to sun or mechanical damage when their unnatural lengthening in cultivation causes them to be too much exposed. But there is a fountain of youth: turning the senescent plant into one or more cuttings. Very few mesembs cannot be rooted if the cuttings are taken at the right time (see 13.1 below).
Many naturally long-lived mesembs are at their most attractive just after adolescence, as Lolita meets Ephebus. Titanopsis, for example, make exquisite single rosettes at two years, while at ten their numerous branches tend to be ragged, leggy, or cramped, with dulled distorted leaves. To maintain an old titanopsis in perfect health and symmetry is thus a real test of skill (even if the “skill” was mostly the luck to have picked a good clone) and is worthy of a show prize. But most of the time it is easier and more rewarding to renew one's compact mesembs by seed or by cuttings.
The most crucial point in mesemb cultivation is the management of water: its controlled but steady uptake, its periodic withholding, its presence in the atmosphere. Mesembs can tolerate poor soil and dim light, but nothing spoils them so quickly and thoroughly as thoughtless general watering. This argues for the necessity of precise individual care. If that seems to border on the precious or fanatical, so be it; perfection is not an unworthy goal merely because it is impossible. Besides, plants are not very interesting when treated en masse. Attachments are particular.
Observing mesembs in habitat, one notes the daily role of dew and fog, the gentle sustenance these give the plants throughout the short-day seasons. Every morning the epidermis is refreshed by dew, which condenses on the leaves and trickles down to the shallow roots. Fog also coats the plants with a beneficial film. Sustained downpours are not common; indeed, when the plants do receive too much rain they rot, just as they do in our pots!
In the wet winter of 1993 I saw thousands of oophytums dying from a grey botrytis-like mold, while their thicker-skinned neighbors, the argyrodermas, were riddled with a lattice-work of cicatrices caused by splitting. This is quite natural, though hardly worthy of imitation. The normal conditions in habitat provide for a steady maintenance; if such an equilibrium were not achieved (at least in good years) the survival of tiny seedlings would hardly be possible.
Emulating Nature's gentler showers, I water lightly but often. This fosters the dreaded shallow-root-syndrome, but the “cure” is obvious: water more often! Repeated light watering has great advantages: it keeps tissue flexible and roots receptive, thus avoiding ruptures at the one end and die-back at the other. And again, it seems to follow what the plants are naturally adapted to, since many wildlings have very shallow, essentially lateral, roots. However, there are obvious exceptions to this: the shrubs and shrublets with deep taproots. These, especially the faucarias and hereroas, dislike prolonged damp; they need to actually dry out between generous imbibitions. Larger shrubs—ruschias, lampranthus, etc.—will take what they can get at any time.
A healthy well-rooted plant should quickly show signs of water uptake. Those fine little roots which can be observed within minutes of misting an unpotted plant are very efficient when a plant is well-anchored. Within hours after watering, or certainly overnight, a slight epidermal gloss like that seen on an over-inflated balloon will be visible, evidence that the roots are working well. One wants to continue this root-building process for as long as possible: a steady reverse fuse, leading to an explosion of flowers. Too much water, and the plant bursts, rots, or loses its roots; too little, and the disheartened fine roots die.
In a humid greenhouse and especially in winter, when freshly watered plants acquire the gloss of billiard balls, the level of epidermal tautness is already high. To avoid collapse or rupture in such an environment it is crucial to maintain good air circulation, with as much ventilation as possible. Better to risk a chill at 34°F than to accept a moldy stagnancy. Good ventilation also helps to avoid condensation drips, which can be insidious, though many plants will happily accept a steady drip all winter long. One could of course staunch the drip or move the fattened plants, but sometimes a paralyzing fascination sets in, like watching a hamster tuck in yet another jaw-stretching nut.
Many people are tempted to take watering just one step too far, but there is normally a warning before the Fatal Drink. If a plant's epidermis shows the slightest cracking, it should be given no water for at least a week. Plants in this condition have achieved repletion and they cannot accept more water without further disfiguration. Complete soil saturation has probably occurred, with root-loss a dangerous possibility. Having lost its roots, the plant is then vulnerable to catastrophic (i.e., meristematic) rot. If one head or branch rots another will soon follow, though it is remarkable that some heads have a life quite independent from that of their twins (two heads really are better than one).
Overwatered plants show leaf-sequence disturbances: bracts are converted to leaves (or vice versa, which shows the intimate connection between these organs) and the result is an unattractive and unbalanced plant. Unabsorbed, the old leaves stack up like fat unanswered letters.
Water quality is very important for mesembs. Apart from pH (detailed under 3.2 below), there are other water-borne problems. Various additives and elements (fluorine, chlorine, boron, minute herbicidal residues, detergents) can affect mesembs, causing strange black spots, chlorosis, brownish pits or lesions, blisters, gross bloating and sudden rotting — a whole hypochondriac's catalog. So it is always best to use rain or good well water. If you must use heavily chlorinated tap water, let it sit for two days before you or the plants imbibe it.
People often ask me for watering schedules and for exact quantities: a teaspoon every other Tuesday? I am wary of such artificial precision, and in any case the least imaginative way to water mesembs is to adhere to a rigid schedule. Schedules (and the false convenience of an ever-flowing hose) tempt one to water all plants on a given bench, whether or not they need it. It is true that most plants will survive such summary treatment. Many will even look terrific, but in a mixed collection there will be a large number of bloated plants along with an inevitable quantity of rotting or withering. Either group your plants together by common requirements, or be prepared to slow down and look.
Nonetheless, a schedule can create a framework of expectations which gradually falls away as one becomes more subtly intuitive, and so I give suggested timetables under each genus. Remember: if mesembs give distress signals at the “wrong” time, you should respond to their needs, all calendar wisdom to the contrary. Eventually you will sense what they want, pre-rationally. Seeing a thirsty plant, you'll feel thirsty too.
It is very important to know when not to water. A few of the true geophytes (Phyllobolus subgenus Phyllobolus, and Delosperma in part) should receive no water at all during hibernation or aestivation; see under those genera. Most of the summer-dormant shrublets require at least a little water all year, enough to keep their roots from burning or drying. During high summer, such plants will accept water—they may even swell up—but they are not really active, and extra water will not result in new growth. Summer-dormant sphaeroids can survive on very little water, especially if they are kept in a cool position and are all wrapped up, but a spray once a week will keep them in much better condition, and one should be alert to the possibility that their “aestivation” can turn active quite early.
Winter torpor, commonest among plants from the Karoo (pleiospilos, hereroas, etc.), requires delicate watering. One mostly waters things lightly to dust them off and to keep red spiders at bay; one will note little or no new leaf-building. The roots will not dry out excessively unless one has a warm winter in a warm greenhouse. The winter treatment of lithops has always been controversial but I favor one or two modest soakings (see under that genus).
Finally, as Suzanne Mace observes: if a mesemb doesn't want the water, it won't absorb it. Indeed few succulents of any sort will actually rot from a single ill-timed watering. A second or third clumsy watering sets off the alarm.
Whether or not it is true that the invention of the hosepipe destroyed fine horticulture, it is certainly true that hoses can make watering too easy, general and swift. But watering cans, bottom soakings, and hand mistings are admittedly too cumbersome for a large collection, commercial or private. So I have found that the single most useful tool for watering is the Fogg-It nozzle, a brass device which directs water through three minute holes. When placed at the end of a hose along with a graduated shut-off valve, it is infinitely adjustable (until it clogs) and can safely be used on even the youngest seedlings, producing a diaphanous mist, a fine shower, or a well-controlled trickle. The shut-off valve allows very close control. It will also give one time to gaze at and to get to know the plants.
I generally refrain from recourse to the fan nozzle. Granted, it delivers a lot of water quickly and relatively gently and is useful for those shrubby mesembs which enjoy deep soaking, and in emergencies: cooling down plants after a hot day. But many highly succulent mesembs will burst at the slightest excess (Gibbaeum nebrownii, for example, is famously prone to crazing); for these the nozzle is unacceptably crude. There are other considerations which militate against the fan nozzle: the delicate roots of seedlings, the necessary avoidance of damp on flowers and fruits, and the side issue of staining (pigments can leach out from old flowers and stems).
Contrary to popular belief, mesemb fanatics do not water only with hand-misters, though they are tools of great utility. The smallest misters are convenient, light to carry around, and require no preliminary pumping; on the other leaf, they only last a few days at the rate I use them, and one's fingers grows weary. (That very feature is a virtue, however; it is hard to overdo misting when excess is so tiring.) Larger pump misters can be awkward to carry around but they last far longer, as they are constructed of thicker plastic. In any case the point is to have a very fine narrowly directed (but not aggressive) jet or puff of water. This is especially important when dealing with tiny plants which are ill or weak. These I mist every morning, attempting not to moisten their neighbors (which do not need the assist). In the ant's house, dew is a flood.
Before I water plants with the Fogg-It, I first go around with the hand mister. This preliminary misting might seem to be unnecessary (since it will soon be superseded!) but it forces one to look around and to see what will need deeper attention later. Otherwise one waters as one examines, leading to miscalculations. It's a bit like salting food before tasting it; the excess cannot be undone. Check your indicator plants: if your imitarias crack, your argyrodermas will soon follow. (These cracks are physiologically harmless, but for the perfectionist and aesthete they become psychological Grand Canyons.) It is a very bad idea to water whilst entertaining visitors. Proper watering—proper horticulture of any sort—takes full concentration.
One of my favorite techniques, but one which has only a partial application to ambiences less dry than mine, is to water plants twice. In early fall, I water them in the evening, not too lightly, but not to the point of saturation (i.e., no water will run out of the pot bottom); overnight they will absorb the moisture. The next morning (or sometimes, the next evening) I will water the plants again, more lightly, reinforcing those which have responded and prodding those which show no change. Sometimes I reduce this fine tuning to a bit of mist in the evening. Mesembs do much of their growing (and sprouting) nocturnally.
With singly potted small plants I usually water all around the edge of the pot. I water at the center of caespitose plants, otherwise the central stem(s) will dry out. (Many clumping plants develop several root complexes, each somewhat independent.) Watering a community pot requires special care, as some plants will have unequal needs and contrary rhythms. Remember, you are watering roots.
If plants are properly watered, the surface of the soil remains undisturbed, betraying no trace of human activity. Of course, a thin mulch of grit or gravel helps one to achieve this illusion; otherwise one finds crevices, craters, and exposed roots. To avoid the deposition of salts on colorful leaves, one can rinse plants with distilled water.
As for thorough soaking: occasionally I do water plants deeply. This is especially desirable for plants which have long roots, plants which are just beginning growth and need the stimulus, plants which need leaching mid-season, and for plants which need protection just before the advent of hot weather or the changing of shade cloth or plastic. But I never give a thorough soaking twice in a row; rather I will alternate this with at least one much lighter watering. A useful variant way to soak is to water pots from the bottom. It is time-consuming, but it is unmatched as a stimulant. It is also good for keeping plants in show condition and for those which tend to rot if water is in prolonged contact with their soft pulpy leaves, e.g., some specimens of Phyllobolus resurgens.
Placing sturdy thirsty plants out in the pouring rain is also a good practice! By the way, indoor mesembs love to be watered while it rains outdoors. However, the extra humidity in the atmosphere makes rupturing more likely.
Mesembs will grow in almost any soil. I have seen them thriving in black florist's compost, in dirt-poor dirt, in gravel or pure pumice (quasi-hydroponically), in fluffy peat, in variants of UC mixes with supplemental pumice. They never look good in fine caking sand, but their general adaptability is otherwise great. It is amazing that around the world, working from such different media, they can synthesize the same pigments.
Despite their omnivorous tendencies, mesembs do have soil preferences, and to respect these enhances their health, color, and flowering potential. I recommend a mixture which is: simultaneously gritty and silty, very well-drained, low in nitrogen, free of visible humus particles, and not above pH 7.5, preferably closer to 6.5. I use only one basic mixture (“mabel-mix”) for all species: two parts loam, one part coarse sand, one part pumice. The only distinctions I make in my mixtures are:
Habitat soil is very heavy and dense. It is often very firm; sometimes it is powdery when dry though stabilized by a top layer of quartz pebbles or other small rocks. In many cases it is mainly decomposed shale, with little humic content. I do not know how well habitat soil would function in my pots, having only taken small samples for soil analysis. The Coles' experiment (all their lithops were grown in habitat soil) suggested to me that it can work exceedingly well, but only in an arid environment.
For most greenhouse conditions, habitat soil and its simulacrums would retain water for too long; as people say, it is too “heavy.” The sphaeroids will easily take up too much water and burst, having no shut-off valve. And even the shrubs will show cracked and ruptured leaves when the soil takes too long to dry out. Yet I have given bags of my leaden mixture to friends in humid climates and they grew difficult plants perfectly well in it. In fact they could only grow these plants (e.g., Dactylopsis digitata) in such a mixture; the orthodox peat-based composts seemed to corrode or stunt the roots after a year or two.
Plants which like a dense clayey soil will look best in mabel-mix or something similarly ponderous; my titanopsis attain a color which every visitor remarks upon. To me they just look real, i.e., they exhibit their habitat colors. I should add that my “loam” is quite silty, with a strong clay component, and it is quite alkaline (pH 8.0–8.5), as are many habitat soils.
Many fine growers favor mixtures entirely unlike mine. Their formulae vary, but they usually involve good quality sterilized “potting soil” (the kind made from composted humus, perlite, and sand) and something to aerate it, e.g., pumice, decomposed granite, sharp sand, or all of these. The more acid the water, the greater the success with such mixtures. When I was a youngster I used Harry Johnson's brand of oak-leaf mold—in those days it was possible to obtain well-composted materials!—plus decomposed granite.
Watering habits have a great deal to do with how well a given mixture works, and water quality inevitably alters the mixture over time. Alkaline, mineral-laden water reacts with peat, speeding its decay or transformation into something nastily toxic and impermeable. And it is not only alkalinity that causes a problem: various salts can compromise your water. Even if your soil mix is acid, it will turn saltily alkaline if your water tends that way. Fortunately, most species will adjust to the gradual rise.
By the time the soil becomes intolerable, it will be time to transplant anyway. More frequent repotting (once in two years) avoids the dangers of excess, but since I only repot every four or five years I need a soil mixture which will hold up. The infrequency of repotting is partly due to time pressure, but it results also from my belief that most mesembs look best when they have been anchored and undisturbed for several years. The leaves or bodies grow smaller, but they also become more compact and more colorful.
There are some genera and species which are very particular as regards soil texture; those which come from silty pans, highly acid rocks, or mossy cliff faces (some of these dislike soil and horizontal life altogether!). These exceptions are mentioned under their genera, as they must be specially catered for.
In general, mesembs are tolerant of a wide pH range. Even the species which naturally occur only in the direst alkaline situations—e.g., Lithops vallis-mariae, with its phenomenal pH of 9.0–9.5—are tolerant of acidity; they will look tougher or more crustily authentic when given a high pH, but most will actually enjoy an acidic life of Riley. Conversely, the true acidophiles, like Khadia nationae, Frithia pulchra or Conophytum turrigerum, will have great trouble with alkaline soil and water, though certain clones will survive prolonged alkalinity. It might be possible to breed them for tolerance; perhaps I am inadvertently achieving this.
If you have alkaline soil and alkaline tap water and nonetheless wish to attempt the beautiful acidophiles, you should use rainwater or an acidifying agent (vinegar, sulphur, Alkaliche, pH Down; ask a local orchid grower). Different acidifiers work on different principles, so some experimentation is necessary. Many fertilizers have acid reactions, which may help, but these reactions can be complex and self-cancelling.
I currently use no artificial fertilizers on adult plants, except for the minute traces I administer via the mister. Excessively strong or improperly balanced fertilizers can cause strange alterations of color (electric blues, screaming parrot greens), disfiguring pimples and other skin eruptions, black spots, floral abortions and conversions, gross obesity, and above all, a strong tendency to rupture after watering. So I find it better to simply leave most fertilizers alone. Now that I have stopped feeding them, the plants are cleaner and more authentically colored.
The safest and most effective way to fertilize mesembs is simply to repot them. Failing this, it is a good practice to mulch long-potted plants with new soil, which will gradually work its way down like wet grout in new-laid tile. Even a very light scattering of soil will help. In any case, the nutritive requirements of most species are so low that it takes years for a soil mix, assuming that it is loam-based, to be exhausted. Very often, any apparent exhaustion is simply a symptom of insufficient watering or of undetected overheating.
The best guide to real deficiencies (short of a chemistry degree or access to that rare thing, a succulent-savvy agricultural advisor) is to look at the color of young leaves. Few healthy mesembs have yellowish leaves, barring a few species in Astridia, Bijlia, Cephalophyllum, Titanopsis, and Vanheerdea. If new growth shows yellowing, especially a streaked yellowing, then there is probably a problem with alkalinity and (consequently) with iron absorption.
Growers who use an “artificial mix” (i.e., the potting-soil-pumice-or-grit blend) will find that at least some of their plants need fertilizer on a regular basis. For this situation I recommend one low in nitrogen and high in potassium; it should be diluted to a twentieth the recommended strength. It is most useful in early fall and early spring and should never be used in mid-winter. At this time most mesembs are experiencing their annual climacteric, and feeding only confuses them.
I do feed seedlings. Physiologically, they are radically different from adults. One wouldn't feed a lean or spicy meal to a human baby (though Koreans accept kimchi at six months), and so it is with young plants, which need to fatten up as rapidly and yet as gently as possible. Thus a daily mist of highly dilute fertilizer water is most beneficial.
For every person who prefers the lean and hungry look, there is another who favors a Rubens-esque opulence and finds plant ribs distressing to see. The what-is-natural argument won't take us very far, since plants in habitat can be as gaunt or blowzy as anything seen in a pot. But there are some natural guidelines to the perennial question: how many active leaf-pairs per branch can be or should be maintained? Lapidarias are often forced into a one-anorexic-pair-per-year mode by their unwitting tormentors, when in fact the plants want to luxuriate, three or four pairs being common in habitat and desirable in a pot. (However, the pairs are never skewed by a chevroned bursting of seams.) In habitat, Pleiospilos nelii flowers from the second pair while the first pair is still turgid. Conversely, argyrodermas, conophytums, gibbaeums, and lithops should never stack up their leaves.
All mesembs will outgrow their pots eventually, unless the entire collection consists of Conophytum achabense. Repotting every three to four years is probably optimal, though some species, particularly conophytums, can survive twenty years of Mother Hubbardry. In any case, you should replant any specimen which seems to be slowing down, or at least you should ease it out of the pot and examine its roots. You may find that these have grown in upon themselves, burrowing in self-created humus, which is not always hospitable. In this case you should knock off or wash away whatever soil is still present and start afresh.
When transplanting plants which have shown signs of salt build-up (whether from fertilizers, unfavorable water, or long-sustained neglect), it is a good idea to bathe them in acidified water for a few hours. This will clean and refresh the roots without damage, particularly if they are then misted forcefully.
With young seedlings which were born into a rich humusy mix and are being replanted into mabel-mix (see under 9.1), I also remove the humus particles; otherwise the larger roots have a kind of shield through which new smaller roots will not easily penetrate. They will eventually break through, but why hinder their course? However, if you have non-alkaline, non-salty water, and use a half-potting-soil-half-pumice (or grit or perlite) mixture for both seedlings and adults, this interfacing problem will be minimized.
When transplanting a plant that has been received bareroot, give it a bath first. If it is very desiccated, an overnight soak in warm water will help to revive it. After planting, place it in a shady spot and do not attempt a brighter ambience for several days. New roots should begin to form within a week or so, but their full establishment takes several weeks, and the plant is not really secure for an entire season.
While transplanting can be managed at any season, it is best to do it when the plants are just about to grow. It is not good to disturb plants which are about to go dormant; it adversely accelerates the process. Wait until the plants have looked dead for several weeks at least! The benefits of repotting may not be evident for many months (or even years); mesembs are sometimes very slow to show their distress or pleasure.
As for pots: mesembs have been grown in tin cans, battery cases, asbestos trays, glazed bonsai ware, ordinary clay pots, and plastic. Plastic is cheap, and it is good where the ambient humidity is low. Clay looks better than plastic, and it is wise to use it if you have a manic and uncontrollable tendency to overwater, and also if you enjoy handling your plants; roots shift less in clay. A few mesembs are always best in clay: Gibbaeum nebrownii is only the most obvious example.
Because of my space problems and dry air, I use square plastic pots. I do not use crocks (well-named) for “drainage,” but I do line the bottom of every pot with pure pumice; for C. burgeri, half the pot is coarse pumice, for dinteranthus, one-third. This is a good insurance and it also lightens the pot (mabel-mix is weighty). But in general the pumice layer is no more than one-fifth the depth of the pot.
After transplanting any plant, do not assume that it is ready to go back on the shelf unprotected. Even the most careful repotting is stressful, so you should watch the plant for wrinkling. New transplants are particularly subject to sunburn because their damaged roots are unable to obtain the water which would otherwise have protected them. Therefore one should always be prepared to shade plants which have in any way been moved. The period of danger varies, but it rarely lasts more than two weeks, after which the roots should have re-established.
Burning can occur even in winter. The most common class of lament is: I changed my shade cloth or plastic / cleaned my glass panes / rearranged two pots on a cloudy winter's day and I only left them for half an hour and boy was I ever surprised! If you do intend to make such a change, it is good to water the plants two days before.
Early signs of burning include a fine rippling of the surface and then a certain bleaching of color. Rippling is reversible if caught quickly enough, bleaching is not. If a plant shows any sign of rippling, it should be covered immediately. Paper towels or napkins work well, and they can be misted or “mesembrocated” often, cooling and rehydrating the plant at once.
It is important (though sometimes rather difficult) to distinguish between normal quotidian wrinkling, the kind to which lithops are subject on all hot afternoons, and the pre-burn wrinkling discussed here. Trivial daily wrinkling vanishes overnight, even without a mist to smooth things out (though this is helpful); it involves no change in color and no epidermal damage. If the raised parts of the wrinkled surface show any whitening or “drying” then burning is well on its way.
The most insidious burning occurs while the sphaeroid species are slumbering. Their thin shrink-wrap is only effective to a certain point, and its protective opacity prevents you from seeing any damage. It is a good practice to keep a few plants having exposed and active epidermata, e.g., argyrodermas, amongst your cono patch; if these plants are suffering, there is a good chance the conos are compromised as well. The safest practice is of course to shade the entire collection on hot days. I used to throw king-size white sheets over my greenhouse on very hot days, especially if these days followed a period of skin-softening fog. The sheets looked awful and the house grew dim, but when it was over 105°F the plants didn't miss the light anyway.
A burned and weakened plant should be treated gingerly for at least one full year; one should not assume that it is fully restored until a whole cycle has been successfully completed. The effects of burning can actually last for two or three years. Do not return the plant to the niche where it burned!
A paradox: some plants wrinkle considerably more the day after watering. I suppose it is due to the rapid expansion of tissue, which later firms up and becomes more stress-resistant. Another kind of wrinkling occurs in winter with the very fat-leaved species like Gibbaeum heathii and Cheiridopsis pillansii. These hide away their new bodies for a long time, and watering feeds the new, not the old, bodies, which have permanent wrinkles and often look burned or bleached. In early spring the bedraggled leaves suddenly pop open, revealing a plump and pristine new body fresh as a guinea piglet, and often a flower bud as well.
Proper watering and stress-avoidance have a direct and beautiful benefit: flowering, the periodic proof of plant health. Mesemb flowers are the greatest pleasure of the year. They are also the key to the most interesting modes of propagation and horticultural improvement. Thus it is disappointing (and worrisome) that some mesembs flower so badly under northern glass.
Poor flowering is mostly due to lack of light and the consequently inadequate transfer of energy. Poor light makes it dangerous or impossible to water a plant amply, and a plant thus starved is unlikely to bud. Also, the very short days of the northern winter are confusing to mesembs. Day-length controls their leaf sequences, of which flowering is just another sequential variant. Many species in Cheiridopsis have a sequence of a long leaf-pair followed by a short leaf-pair, and then by flowering bracts (in effect, another short leaf-pair) plus an incipient long pair. In the short-day northern gloom, the plants manufacture endless variations of one long sterile pair after another; this is equally true for mitrophyllums, monilarias, and all the other dimorphics.
The best solution to this problem is of course to move to Namaqualand or New Mexico. Failing that, you can maximize the available light by placing shy plants on high bright shelves from late summer onwards. Give them the most favored position and do not assume that defeat is inevitable. Even the very shy Monilaria globosa has flowered in Hamburg! Frequent but shallow watering will help prepare the plants for flowering, as will bringing the plants into growth early, as suggested under 1.1 above. It is also possible to augment natural light by using the new high-intensity lamps developed for aquaria.
One often reads that plants will flower only if they “think” they are on their last legs, an argument for starvation. This is dramatic and touching but nonsensical, like the last perfect utterance of the Dying Poet. Very weak plants cannot even form buds! It is notable, however, that plants on the point of flowering hardly ever rot, so it is evident that they do marshal resources for their annual tryst. And it is true that if plants are overfed, they can convert embryonic buds back into leaves. So perhaps there is a tiny granum of truth to the idea that fat plants grow complacent; untouched by the hot breath of mortality, they do not bother to flower. But in fact these gargantuans normally flower very well, bearing huge fruits. If you want to produce a lot of lithops seed, give your plants ample light and food. They will be grotesque but most productive.
Few compact mesembs have long flowering seasons. That would contradict their basic strategy: the production of one, two, or three leaf-pairs, the last bearing the flower(s). However, some genera will flower erratically over a period of some months, e.g., stomatiums and schwantesias.
Almost all mesemb flowers are protrandrous; the anthers shed their yellow burden before the stigmas are quite ready for it. And since most mesembs are self-sterile, fruit production needs two clones in simultaneous flower, or one clone plus some stored pollen from another. (Pollen keeps well in the freezer, if gathered on a brush and stored—brush and all—in a tightly sealed jar.)
On the average, flowers last for about a week and are maximally receptive on the fourth or fifth day. Most plants in or from a given population have a high degree of synchronicity, so floral overlap is usually not a problem. It is important to avoid the wetting of flowers via the hose, misting, or condensation. Moisture destroys the pollen by agglutination and traps the stigmas. Sometimes it even welds petals together. But if a healthy-looking bud seems not to open, consider that it might be night-active!
For pollinating widely expanding flowers, small paint brushes are best. I have seen people using fingers on their lithops and wondered how they kept digital track. A fine nylon filament or cat whisker is best for small tubular flowers. If you pollinate several things in a row, be careful not to touch any pollen; you can transfer it unwittingly. I have even seen accidental pollination caused by gold-nosed visitors sniffing one flower after another.
If you want offspring with as much diversity as possible, pollinate a given “female” with pollen from as many other clones of her-his species as are available. If you are attempting to work in a certain direction—for example, toward bolder patterns—it is better to narrow the field to a single pollen donor, one most nearly matching the stigmatic parent. Presumably you will have chosen her-him for one or another unusual virtue. To make hybrids, you can try anything with anything, but you should record exactly what you did. You might come up with something fascinating or implausible and wish to repeat it.
Despite the general self-sterility of mesembs, there are some species which are perfectly self-fertile and some individuals of normally self-sterile species which occasionally (or always) break the rules. Sometimes it is enough to apply the plant's own pollen to its stigmas repeatedly, not just once, but for three or four days in a row.
Often one can induce self-fertility (or “selfing”) via the application of foreign pollen. Fenestraria pollen is sometimes effective as a catalyst for selfing glottiphyllums, sometimes not; it is the same with pollen of Conophytum herreanthus and any of the monilarias. It is always worth the attempt in cases where you have only one clone of a rare species or a particularly fine clone which you would like to increase from seed. Testing self-fertility is not easy; one must guard against the unplanned and mysterious pregnancies caused by errant bees or moths.
Mesemb fruits are dry and woody when ripe. The process takes anywhere from a scant month (Rhinephyllum broomii) to a year and a half (Conophytum smorenskaduense, the elephant of the family). You can easily tell when fruits are ready: they open spontaneously when wetted. They need no further ripening and their contents can be sown immediately. Some seeds are ripe and sowable before the capsules are fully dry (Bergeranthus, Hereroa); it is startling to see brown seeds emerging from still-green fruits.
I know of very few seeds which need the influence of age or environment after the fruit which bore them is dry. Some species of Dorotheanthus need aging (or abrasion?), and some erepsias, like other fynbos species, (2) need the heat or smoke of a quickly passing fire (though I cannot recommend such for domestic use). The fascinating and aberrant Lampranthus scaber germinates very slowly, as do certain species in Phyllobolus, which seem to have a kind of time-release formula, like cold tablets. But lithops seeds will cheerfully germinate seven months after the appearance of the flower which formed them; so will faucarias, glottiphyllums, etc.
Fortunately, most mesembs are easily reared from seed. They want very much to grow, after all, and there are only a few troublemakers in the whole of Mesembryanthema. Most of these (like Saphesia flaccida and those weedy alpine erepsias) are not really that attractive in cultivation, which is not to deny their botanical appeal. But there are some small precautions which make things easier for the sower. When cleaning mesemb seeds, carefully separate the chaff from the “wheat” and discard it. Some people crush and sow the whole lot, but the chaff is a good incubatorium for fungus, and when swollen like a sponge it prevents rootlets from finding the soil. Never sow seeds in a hurry or after drinking tremble-strength coffee.
Certain highly desired species are universally problematic, and most of these have tiny seeds. The great and most common mistake is to treat the seeds as if they belonged to a succulent plant! They do, of course, but you will much better luck if you pretend that they are begonias or petunias. The main difference is not that they need less water than petunia seedlings (they are about equally unsucculent at first), but rather that they need much more ventilation, being so highly prone to damp-off. There are, however, many easy tiny-seeded species, e.g., Lithops verruculosa.
2 “Fynbos” is an Afrikaans term for certain plant communities in the southern Cape, comprising Ericaceae, restios, pteronias and other sclerophyllous plants, geophytes, and a few succulents.
For sowing tiny seeds, mabel-mix is simply too dense, so I use a more or less orthodox formula: two parts screened sterilized commercial potting-soil, one part pumice screened to 3 mm, one part sharp sand. The mix should be baked for at least two hours at custard-setting temperature and left for a week. I prefer tiny pots, 2×2 inches or even less; their rapid dry-out time is helpful against rot. Tiny seeds should be covered only very lightly when sown; larger ones can be covered to a depth matching their length. I generally germinate the small-seeded mesembs under lights. (The main exceptions are dinteranthus and lithops; see below.)
Sowing under lights can be done at any time of year but it is probably best if done during the short-day months; winter is cooler and generally less muggy, and one has more time then to attend to the process. If the lights are near a source of natural light, all the better. The lights should be kept on or off in twelve-hour cycles. The pots can be placed very near to the lights—eight inches or less—in a room kept at about 70°F; there are very few mesembs which actually prefer cool temperatures for germination, though many will tolerate them.
It is best to have a separate room or chamber for sowing purposes. You can keep it cleaner (I allow no shoes near mine) and can better control the ambience, excluding, for example, quadrupeds, oily cooking fumes, and household insects.
After soaking the sown pots in a bath of distilled water, I cover the pots with a sheet or film of transparent plastic, which should be tight enough to quickly acquire a fine coating of water beads. If this coating is still absent after half a day, the pots are too dry or the plastic is too loose. If the coating is so heavy as to form tear-size drops, the pots are too wet.
After four days the cover should be loosened, germination or not, as otherwise the soil will begin to sour. By the fifth or sixth day the cover should be entirely removed and a fan should be placed near the pots to provide constant air movement. At this point pots can be soaked from the bottom once again, briefly. (Further soakings are usually too dangerous.) If you are willing to use fungicides your safety margin will be far wider, but I avoid them, partly because I prefer circuses without nets and partly because fungicides do not discriminate. They are bad for humans too.
A watched pot never boils or sprouts, and sometimes seeds will take far longer than one expects. Anywhere from three to four days for cheiridopsis (the minimum is two), to a week for thick-leaved things like faucarias. Lithops and conos take three days to three weeks or more. The challenge is to avoid sour soil and rotten seeds during this period; over-eager watering leads to drowning. Once the pots have been exposed, they should be misted at least twice a day. When the seedlings have emerged, add a trace of fertilizer to the misting water. Seedlings have insatiable appetites; tough authenticity can come later in their lives. As the seedlings expand I gradually mulch them with fine grit; this combats algae and supports any seedlings which have a tendency to flop.
For the less delicate seeds I recommend sowing in summer, outdoors, in a screen-covered frame. If the screen is very fine it will break up a moderate rainfall safely. A second cover, made of plastic or glass, can keep out rain when the moisture proves excessive. (Rain water is wonderful, but a little too much and a whole lot of seedlings can turn to jello.) The initial use of a tight plastic cover, and the advice about water-beading, are as appropriate out of doors as in. And again, proper ventilation is critical, though this is of course easier outdoors. The soil-mix should be similar to the mix discussed above under 3.1, with an addition of ca. 30% humus. It is not as important to sterilize it as it is with the finicky tiny seeds.
Summer growth is by far the best growth; in a few months you can obtain seedlings three times larger than those sown the previous spring and four times larger than those sown the previous autumn! As an example, take Sphalmanthus herbertii, a charming dwarf caudiciform. Seedlings from October 1993 flowered sparsely in November 1994; seedlings from April 1994 flowered poorly in December 1994; while seedlings from late August 1994 flowered well in January 1995.
Also, summer growth is far more stocky and compact, and the plants retain this as a permanent advantage. The only mesembs which do not do well with al fresco summer sowings are most of the conophytums, though I am now experimenting with late summer for these. For all other genera, I recommend high summer. Even the “winter-growing” Mitrophyllinae (which do have quite small seeds) will grow very well if sown outdoors in summer. Lithops and dinteranthus seeds will germinate very quickly when the temperature is around 100–105°F. As long as they are kept slightly damp, they will not burn up, and under these conditions very rapid growth is possible. The cotyledons can reach a diameter of 3 mm in a few months; the bigger the better!
One of the best things about seed-raising is that one can use multiple crops to stagger or distract your impatience. With continuous crops, you always have something new and something about to mature, so no single pot becomes the victim of obsessive impatience; the three-ring circus gives one a feeling of movement. Horticulture, after all, is a mode of articulating and feeling time.
I should report that many growers report fine and rapid results using the familiar baggy method, which involves permanently covered pots. I cannot manage it! I have better ways to grow algae—and the baggy method tends to produce sappy seedlings. It is best for haworthias and other plants which can quickly recover from stretch marks. It might be effective for some difficult mesembs, e.g., Conophytum depressum, which seems to elude most growers (it simply dries up). The exposed pot method necessitates a lot of inconvenient misting for this and similar species. Some growers rig up an automatic misting system to deal with the problem.
It is not advisable to transplant seedlings until the first true leaves have acquired their maximum succulence. At this point the cotyledons will have lost their powers and their rot-proneness; they may even have withered away. (It is possible to transplant even week-old seedlings but it is a time-consuming stunt, and a high mortality is probable.) I generally transplant seedlings of robust mesembs within three months of their sowing. For sphaeroids, I wait half a year or more.
If your seedlings are very crowded you will have what Schwantes called a “starvation culture”—plantlets in suspended animation. In this state even competition is nullified. You can keep these “cultures” going for many years, waiting for the mythic rainy day when space will be available, but you must feed them very lightly. When you do transplant them, their rapidity will match their gratitude.
When planting a seedling of whatever age, make sure that its taproot goes straight down; if it curls up or twists upon itself, the result can be prolonged stasis. In summer I water transplants immediately, to moisten the roots and to fill in those empty pockets. In winter, transplants must be handled more gingerly, and a light misting only is advisable at first. This can be repeated a day or two later; normal watering is safe after a week or so. For hybrid seedlings, which are weak for their first year, special care is necessary: extra shade and food.
Succulent plant breeding has been very much neglected. Traditional reactions to the idea of trying to “improve” mesembs have several aspects, not all of them rational. To some it seems arrogant or unnatural to imagine that Nature's beauty can be improved; there is also a general fear of humanly applied eugenics, which spills over into the vegetable realm; and a fear that locality data will be lost through multi-populational (or multi-specific) crossings.
As for arrogance: Nature is perfect in her realm, but that realm is not under glass. So there is nothing hubristic about trying to breed a Cephalophyllum alstonii which will not require a two-foot pot and months of winter sun to flower richly—given that its scarlet flower is the thing we most cherish about this plant. Such breeding is not only possible, it is almost simple. It has been widely practiced in the other parts of the horticultural world. The “improvement” of succulent plants does take much time, but so does the breeding of roses. And as Goethe said: the unnatural, that too is natural.
Partly because of the fear of eugenics, we in the succulent world have been practicing dysgenics with a vengeance, propagating the easiest and weediest clones! The funny thing is that a taste for compactness and elaborate patterning is universal. Most of us want the same sort of beauty, but we often neglect or shun the best means of achieving it.
Data collection reaches its apogee in the succulent world. (It has a rough parallel with the world of pedigreed cats.) But as I have argued elsewhere, data doesn't really mean much to the typical collector except symbolically, and I am not sure that it should. How many of us make herbarium specimens anyway? The concern for purity is another matter, and of course “data” equals purity; the converse is not necessarily true. Pure plants can be derived from a single source (i.e., from a single population) but they are often “refined” to the point where data merely indicates their starting point.(3)
Extremes of individual beauty in plants (or people) are abnormal, not unnatural. (I do not mean the normal beauty of every healthy organism; I mean the superlative beauty, usually involving an extra degree of symmetry and heightened coloration, manifested here and there.) But the recent discovery of a wild population of Haworthia truncata in which many of the plants looked like the best of the Japanese star-marked “cultivars” should tell us something. Perhaps at the well-known localities the pretty ones have all been collected away, as has happened with some lithops!—in which case we breeders are merely restoring what has been lost.
3 It is of course illuminating to collect, record, and analyze plant data, but this doesn't imply that one has also to collect data-iferous plants. The functions are separate though it happens that they are often conjoined.
Increasingly, odd color sports are turning up in cultivation. The main reason for this is probably the vastly greater number of seedlings raised during the last two decades. Not only in Lithops, but also in Pleiospilos, Conophytum, and Dinteranthus, one finds “green albinos.” In normally green-skinned genera or species, albinism is of course harder to detect, but it is still possible to spot it.
There are more and more floral freaks too. Mesembs with purple pigments in their petals occasionally lose them, giving us white. I recently flowered two hundred seedlings of Conophytum wettsteinii, which is normally magenta: one was pure dazzling white. Even more rarely, one finds a loss from yellow to white.
The propagation of these attractive variants can follow the route of the backcross (the color freak crossed with its mother), or selfing can be attempted via the use of odd pollen, as mentioned above under 8.2. Stabilization takes a minimum of five years, more often ten.
I advocate some unusual things, and one of them is deliberate hybridization. I have been convinced through my own work and that of other breeders that there are wonderful possibilities in this line (see my “Conograph” for more details). However, most hybrids are ugly, drab, and confusing; one has to be ruthless to achieve good results. One also has to have patience and ample space. It takes about 200 seedlings to find an exceptional one.
A notable character of most hybrids is that they are not tolerant of heat. Thus you must protect them in summer, otherwise they will go pink or yellow or ghostly dead white; the chlorophyll retreats or simply burns up. This heat intolerance might well explain their comparative rarity in habitat, for the overt crossing barriers between sympatric species are often weak.
Hybrid work has had a significant impact on our understanding of mesemb systematics. Here I will only mention one example: virtually all the Mitrophyllinae will cross both within each genus and between genera, which might help to explain the numerous bizarre “species” in this group.
Under each genus I list the successful intergeneric hybrids I've produced. I do not list the failures, partly because it would take up too much space and partly because two or even ten negative attempts are no proof of absolute failure. (For example, I was always convinced that Cephalophyllum × Fenestraria would be possible, and seem at last to have managed it; but until last year I would have recorded “failure.”)
I don't list all the interspecific crosses within a genus, though I do give some examples of crosses with horticultural promise. In many cases the work is at such an early stage that I can only say that the seedlings are healthy, e.g., Conophytum 'Tetraburger'. The best, but also the slowest, possibilities lie in the more complicated multi-species crosses, e.g., Conophytum 'Acuturge' (C. acutum F × C. burgeri M) × C. 'Ceresiacum' (C. maughanii subsp. armeniacum F × C. obcordellum var. ceresianum M). This line allows one to produce (or to “interface”) secondary combinations of species which are otherwise in compatible.
That a crossing succeeded once is no guarantee that you will be able to repeat it or that the offspring will be the same the next time. In general we find the classic Dominant Mother Syndrome, but sometimes this is reversed. First generation seedlings are often highly variable. Save them all; if they can overcome their initial weakness, the runts might be the best of the litter.
Much mesemb propagation has traditionally been accomplished not by seeds but by vegetative increase. This was the case with most sphaeroids until recently; seed was unavailable. And it is still the mode of choice for many of the long stemmed mesembs used for landscaping.
All mesembs have stems. In the shrubbier species this is obvious, of course; in the compact species like faucarias, stem-building is only evident in older plants. In the so-called stemless species, the stems are very short and are covered up by the fleshy leaves. But eventually the stems of all mesembs are exposed: growth has to proceed upwards, however slowly. At this point you have several choices. You can simply allow the plant to fulfill its elongate destiny. Or, you can repot the plant more deeply, thus burying the offending stem; prune the plant to make it shorter; or turn the whole thing into cuttings, discarding the old plant. (Schwantes spoke of curing the “bad temper” of an aloinopsis in such a way.)
When pruning plants with long internodes (or taking cuttings of them), stems should be cut at a point several nodes below the most active leaves. Always water plants well shortly before you prune them. Freshly pruned shrubby mesembs look rather stark for several weeks, but eventually the operation will pay off in shapelier growth. You can root the superfluous branches but you may not need this much vegetable mass unless you have outdoor plantings or many friends.
Cuttings of the “stemless” species do best if taken very near the growing point. With the sphaeroids, if you allow a more generous length of stem, you will find that the plant usually roots not from the long stem but rather from points very near the meristem. Indeed, the long stem sometimes seems to get in the way. Pieces without a meristem can even root — this has happened with Conophytum bachelorum—but of course they die eventually.
The best time for cutting is when the plants are in their most active phase, not during their flowering season and not when days are at their shortest. Use your sharpest knife. After taking the cutting, you can apply rooting powder to the wound though it is not really necessary; its primary virtues are usually a built-in fungicide and the instilling of artificial courage. Cuttings should be inserted into a coarse medium; pure pumice is effective, as is very sharp sand, or a mixture of gravel and perlite. (For that matter, your normal potting mix will work almost as well for most plants.) Cuttings should be placed in a half-shady position, below the bench but not too cool or dim. Bottom heat is only necessary if the area or season is too cool (under 40°F).
Once they have calloused, which takes only a few days, cuttings can be watered rather generously. Since they are not actually absorbing the water (lacking all roots), there is little danger of overdoing it initially. Some roots should strike within three weeks. Once rooting has occurred, caution must set in; as soon as one sees the signs of stiffening and (in the case of conos and lithops) of a fresher green at the bases of the bodies, watering should be reduced. After a month the plantlet can be repotted in real soil and placed in its permanent position.
Occasionally plants will not root as rapidly as expected. A cutting of an undescribed cheiridopsis, taken in South Africa fn July 1993, rooted only in November 1994! (In the meantime, the plant was sustained by an occasional misting.) Sometimes conophytum cuttings taken in autumn will wait until just before the summer to root, presumably because new roots are actually initiated by the newly formed concealed growths. Few plants can resist the pull of spring.
Certain shrubs are quite difficult to root. Drosanthemum speciosum usually eludes me; it would be easier with a misting bed. Most members of Mitrophyllinae are awkward to root as well. It helps to mist the cuttings with fertilizer water. Namibia ponderosa is almost impossible for me; perhaps I am defeated by my dry air.
If you are producing mesembs en masse, you will find it effective to cut and recut. For example, you can totally decapitate a clustered conophytum and root all the severed heads, which will divide abnormally well the next season, since each head now has its own exclusive root system. Then you divide all the divisions! Thus within three years it is possible to turn one head into thirty or forty. The only trouble with vegetative propagation is that one ends up with more of what one already had. Seed-raising is less predictable and more challenging, but it is also much more interesting.
Potted mesembs dislike movement, even the casual lift which takes them from one corner of the greenhouse to another. It is not only that a new orientation can distress them, it is also that sharp movements can destroy fine roots. If a plant seems very happy in a given niche and has enjoyed that sinecure for at least one full year, do not move it! Growers can be amazingly (if unconsciously) brutal. Mesembs particularly dislike automobile travel. And when travelling through the post without their cushion of soil, they can show great distress, though generally they are not permanently disturbed.
Mesembs react strongly to wind, another form of movement but a natural one. The breezes and gales of Namaqualand sculpt plants into compact forms, especially those growing on the sandblasted coast; Neo-Lamarckians could make much of that. Artificial wind thickens the caudexes of cultivated pachypodiums, and the same must apply to the compact fat-stemmed mesembs.
However, short of growing plants outdoors or in a wind tunnel, all one can do is to provide as much ventilation as possible. It is certainly a good idea to have a fan blowing in your greenhouse or aridarium at all times. This will also help to combat fungus, of course, and provides some heat relief. For some reason, plants in hanging pots often do exceptionally well. I imagine that the free air and lack of competition are important factors.
Back during the period of flower power, “companion planting” was widely practiced. We had peas with carrots, beans with squash, grass with grass. Today I sometimes plant a weak mesemb with a stronger one, or sow two unlike species together, hoping that the one will stimulate the other. But it is not a good idea to place cuttings of two (or a single) species too close together—you will see differential growth rates, and some of the cuttings will be starved. If you try to redress the balance you may rot the usurpers. Never attempt to weave cuttings into an artificial clump; the results are unconvincing and lopsided.
Lithops and conophytums can get along just fine in a single pot, which tells us that a certain independence is possible even at close quarters, and that for all our anxious timetables, flexibility is real and opportunism is rampant. Both in habitat and in pots one can see an active lithops right next to a sheathed conophytum! If you want to grow dwarfs from several families together, you can try conophytums with tylecodons or bulbines.
There are two kinds of introductions: plants new to one's collection, and those altogether new to horticulture. Both kinds require some sensitivity. For the latter I can only say that a little misting never hurt anyone; it is of course difficult to tell if a blind-dated and travel-shocked plant is coming or going. For the former, try a position where no plant has ever had trouble. Most greenhouses have their safe spots and their dangerously hot or cold ones. In any case, do not add a potted plant to your collection without dipping, washing, and repotting it first. Otherwise you may add more than you bargained for.
Mass importations, in the sense of raw collected material, are at long last out of fashion. However, many people import nursery-grown seedlings or cuttings from the opposite hemisphere, and the adaptation of such material does cause some problems. The main rule is to establish a new root system as soon as possible, even at the risk of premature growth, leaf-stacking, and bursting. The following year the plants will slowly absorb the excess, or if they do not it can be peeled or trimmed away.
Occasionally you will find that a certain plant fails to thrive, sulks badly, and then fails to grow at all despite the most careful attention. This is when intuition come into its own. I can only suggest a few tricks: a radical change of scene; an enormous overdose of water; a sojourn in the rain; placing the whole plant, pot and all, in a deep bucket of water and waiting for a day; one of those malodorous elixirs featuring vitamin B1 (they really do help); or a radical change of soil. You have nothing to lose. First do no harm, as Hippocrates commands us.
Mesembs are tolerant of extremes. They can endure temperatures in excess of 120°F if well ventilated. What they most dislike is hot still air, which desiccates and roasts the plants, so weakening them that they are unable to form new roots, the old roots having burned away. To reroot, they must first experience rehydration, which, lacking roots, they can hardly manage! In very hot conditions you can move vulnerable plants to a cooler spot, perhaps on the floor.
However, many mesembs will thrive at high temperatures as long as they are watered adequately. Argyrodermas grow strikingly alabasterine; far from being dormant, they are receptive to water during summer as long as they have not previously lost their roots during a spell of caution. Pots at the end of a row are the most exposed to heat. Heat affects the water balance within a pot to a surprising degree, and the smaller mesembs are much affected by this. (Remember that plants with moist roots are far less likely to scorch.) Winter day-time temperatures under glass are often too warm. This can lead to a forcing and softening of growth. Again, good ventilation is critical.
As for low temperatures, most mesembs can tolerate mild frosts — 25°F—for short periods. But I do not recommend the experiment. For one thing, frost damage can take weeks to manifest itself and one cannot always be sure that a given plant has coped well until it is too late. For another, there are some mesembs which scar at 30°F (e.g., jensenobotryas) and some, especially the coastal juttadinterias, which can die after a few hours of 28°F. Very much depends on the health and turgor of the plants before they suffered any onslaught. But in any case, 38°F is a safe minimum.
Horticultural tortures do not interest me much, and my knowledge of frost tolerance is chilled by a slight disapproval. However, this prejudiced reaction is partly sentimental, partly silly; many mesembs obviously do not mind freezing cold in the least, and some will thrive in it, Delosperma nubigenum being the most famous example.
Conducting inadvertent and painful experiments (via power failures, gas lacks, penury, etc.), I've found that many coastal mesembs (e.g., Juttadinterias) are very tender, and that inland species, particularly the rough-leaved ones from the high Great Karoo, are much more spartan. These Karoo mesembs can mostly handle 10°F at least. So can lithops; if they are kept dry, most of them will handle short periods of 0°F.
Experimenting with a rockery, you will find that many species will look better than they do in pots and, if established in early spring, they should be tough enough for a winter of +-10°F. But do not experiment with plants you cannot bear to lose. Do give the plants as much drainage as possible. If you expect them to endure the full summer sun, be prepared to water them amply; otherwise, they must be protected by artfully placed rocks and shrubs. We should not be surprised that so many mesembs run rampant when planted out in a bed or generous pot; the surprise is how well they can restrain themselves in pots. In effect we turn many species into bonsai under glass.
Many mesembophiles start out with a few shrublets in a rockery or a row of lithops on a windowsill.(4) These situations will accommodate a limited though diverse range of plants, but eventually room runs out and one considers the option of a permanent shelter.
If this applies to you, and you live in a frost-free area, a simple screen to keep out birds, insects, and non-human pollinators is enough. Where frost is possible but rare, you will need some sort of removable siding. If frost is frequent, you will need a fully enclosed shelter, i.e., a proper greenhouse, but it should have as many vents as you can afford and preferably a screen-door at either end. An exhaust fan will help to alleviate heat build-up, but it is expensive, noisy, and distressing to the planter if not to the plants. It is nicer, and not as impractical as it sounds, to have a fully removable roof.
If you wish to create an adaptable, comfortable, multi-purpose greenhouse, consider the following suggestions. Whatever you build, it should have as much cross-ventilation as possible; it will breathe better if it is much longer than wide. It should not be so large that its bulk will encourage the neglect of its inhabitants. All surfaces should be within easy reach. Orient the structure so that its long axis catches the morning sun. If possible try to filter some of the hotter afternoon sun by the strategic placement of shade cloth, by applying an ephemeral white wash, or by planting winter-deciduous trees.
Some plants like to bask all day, so at least one warm high shelf for these Shadrachs is desirable. Conversely, you should make a dimmer corner for malcontents and new arrivals. This sanatorium can be a shelf under the bench, but it should not be so dim and inaccessible that you are encouraged to neglect it, nor should it be too chilly. It is a good idea to have a heating cable installed on the bench, as it will help to speed the rooting process.
Ideally the maximum greenhouse temperature should not exceed 105°F (measured near the tallest plant); the minimum should not dip below 35°F (measured on the floor). The maximum night temperature in winter should not exceed 60°F and should preferably be closer to 45°F. Otherwise you will end up with a kind of forcing chamber.
If, when standing in the greenhouse, you can feel the prickly ultraviolet rays eating away at your skin, you need to find some shade-cloth and a sunscreen. I actually prefer an easily erased whitewash, but have used various grades of shade-cloth. The white cloth used as a weed barrier for gardens is effective when hung from the ceiling of the greenhouse. You can contrive localized shade by placing a double layer of nylon screen, or a square of cheesecloth, above a pot.
No single ambience can suit all plants. If you cannot contrive multiple Edens under one umbrella (mixing metaphors as broadly as possible), confine yourself to plants pre-adapted to your particular situation. If your greenhouse stays stubbornly oven-like, grow pleiospilos and dinteranthus. If you have a cool alpine-style house, raise conophytums. If orchids thrive under your humid conditions, try marlothistellas and delospermas. If you only have a window sill, raise tiny plants; it is surprising how many will fit in a small area. They can actually grow very well next to glass, indoors, though overheating is a real danger.
Heated cold frames are another good possibility, but they can be awkward to manage where weather is unpredictable. Oddly enough, mesembs are most popular in the northern European countries where they must be raised under glass or plastic. These countries have long traditions of succulent cultivation and general horticultural virtuosity (the biggest gooseberry, the most redolent lathyrus). But mesembs could hardly survive above the 50th parallel and behind bars if they did not have a certain built-in adaptability. Indeed, some species are perfectly suited to European conditions, especially those which come from shaded crevices, e.g., many of the conophytums. Their principal enemy in Europe is botrytis, which attacks the floral tubes and then penetrates inward and downward.
4 My ex-landlord knew that I was nutty when he once looked through the window and saw me watering what he'd thought was a “rock collection.”
Every day you should examine every plant. If this seems too ambitious a task, ask yourself if you have too many plants. Use your senses: pay attention to small changes in color, texture, and odor. If you cannot remember what your plants looked like yesterday, you have been watching too much television.
Certainly you should examine daily those plants liable to harbor pests (stomatiums, hereroas) and those most prone to rot (soft-bodied sphaeroids). And you should not only look, you should use your nose in the process. Saturated soil has a peculiar odor; so does rot. It is good to lift a pot or two, to examine a plant on all sides, but do this gently. Since red spiders hide in neglected corners, do not neglect them.
The neater the greenhouse, the more inclined you will be to make your inspections and visitations thorough. It is also good to occasionally turn your perspective upside-down: enter your collection pretending to be an inquisitive visitor. Why is this plant looking so wizened? Why have you not placed it over there, where the taller one will shade it slightly? Why is this label illegible? When will that cracked pot finally collapse?
It is good to check things by looking from the outside in; you will see something you've missed. When I was a youngster in California, I used to lie on my belly and gaze at my rockery mesembs from ground level. This allowed me to enter their world and to leave time aside.
Mesembs are somewhat attractive to a variety of insects, but they are apparently not as tasty as even the toughest asclepiad or cactus. Plants in good condition should be nearly pest-free, particularly if they are grown in peatless mabel-mix. Nonetheless, there are several pests to watch for: red spider, mealy bug, caterpillars, and sciara flies.
Red spiders are perhaps the worst pest because of their guerrilla tactics: suddenly they appear and attack. They favor rough-leaved species, the same Karoo ones that are so famously hardy. But if I mist the vulnerable plants every day, they are never attacked by red spider. If I am gone for as little as one week, they move in, along with their various relatives. (The rapidity of their take-over suggests that they are always present, waiting in the wings, like kitchen weevils.) I do not know quite why the daily misting is so effective; perhaps the spray destroys eggs or in some way subdues or alters the redolent compounds that attracted the pests in the first place. In any case I will continue it.
Mealies are sometimes attracted to lithops flowers, descending from the pedicels into the hidden new hearts with disfiguring results. They can also lurk within the skins of old matted conophytums. The “other” mealies, those which sap the roots, are invisible except by their effects. They often cause mesembs, particularly sphaeroids, to grow abnormally tall. Aerial mealies can be fatally painted with isopropyl alcohol. To kill the root-dwellers you can dip the roots in a bath of alcohol and liquid detergent, but you must also briefly dip them in water before and after the longer alcoholic baptism. Otherwise the alcohol will begin to pickle tissue within a few minutes.
There are many little chewing insects; I call them by the generic “caterpillars” out of ignorance. The worst ones are those burgeoning sigmoid devils which feed by night and hide by day. I inspect plants every night by flashlight, as their devastation can be swift. Small thrips are a danger not so much to your plants as to their possible progeny. They can move unseen from one flower to the next. If you cannot eradicate them, you can try to beat them by pollinating the flowers before they do (!) and by separating related (i.e., readily crossing) plants. Mice are fond of conophytum fruits, which they will gouge out from the bodies; I even wonder if they are partly responsible for natural dispersal. If you have them, keep a hungry cat on hand.
Sciara “flies” are the prime nemesis of seedlings; they love to burrow in exposed humus and conduct their vampirism from below. It is a good practice to mulch your seedlings with a layer of grit, which will strongly discourage the flies. (It will also help to prevent an algal carpet.)
It is wise though unpleasant to spray your whole collection with a systemic insecticide twice a year. I currently favor Orthene; Knoxout is also effective. Neither works particularly well with alkaline water, however, so the water should be acidified for this purpose. For as long as you can bear it, stay away from your collection after you have sprayed; sow seeds, or do your taxes or something else you have neglected in favor of the greenhouse's charms.
Rot is only a minor problem with mesembs if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much. If you find one head or branch rotting, cut it entirely away, down past the meristem or the nearest major branch. If caught early enough, the rot is unlikely to spread. (This is why daily inspection is so important.) Still, it is always a shock to realize that our plants are just little bags of water; they are not nearly as solid as they seem, and they can leave without saying goodbye at all. Chinosol is a useful prophylactic and curative, but it has to be administered via water, an excess of which caused the rot problem originally. Alcohol also has its place: it should be used to clean all of your surgical arsenal, and your hands. It is best to burn any rotten material.
A too-rapid abandonment of tissue is dangerous for any mesemb; it can lead to (or may already indicate) rot and it certainly shows that the usual osmotic or hydraulic transfer of resources has not taken place. Nonetheless, at certain times of year, healthy mesembs may change color or texture quite quickly; once one is accustomed to it, this is no more alarming than the autumnal reddening of maples. The horrid age spots seen on many older leaves are also harmless; they are caused by the decomposition of tannins.
The anisophylly (leaf-inequality) which is found throughout the whole family even manifests itself behaviorally; the leaves of a pair will not respond in quite the same way and one will often be quite obviously healthier than the other, being slower to dry up and less rot-prone. I favor the weaker leaves when I do my misting, which amounts to a very mild foliar feeding, and if desperate will apply fungicide to a weak leaf.
Cathryn Mangold once taught me a very valuable lesson. Back in the 1970s, when Tanquana hilmarii was rare, she gave me a beautiful seedling and warned me that it was rot-prone. I couldn't resist misting the little plant; I loved to see its ruddy sparkle. Naturally it rotted. I told Cathryn and she said: “I'm cross with you for killing it.” This seemed a harsh judgment until I realized that the death was truly my fault.
Some horticultural loss is inevitable. It is impossible to have everything in your collection at the same level of perfection simultaneously, particularly if you are continuously adopting new material. But a great deal of loss is the simple result of inattention and willfully repeated stupidity. If you adopt too many new plants, you will probably neglect the old.
The Nineties are the Age of Personal Responsibility or, at least, an age in which we suddenly prate about it as if it were a new discovery. But responsibility applies to your collection as much as it does to your life, if these forces can be distinguished. You are responsible for the quality of your plants, for the mode of their acquisition, and for the sharing of their beauty with others.
Most collectors dislike contemplating the future of their collection after their demise. Most of us dislike thinking of our demise, period, and horticultural collecting is an amazingly good distraction from the brute fact of our mortality (perhaps that is why the death of a favored plant is so inwardly painful?). Collecting and tending plants becomes a powerful reason to rise each day: what's new in the greenhouse? In a sense the collection must die with its animating force, the collector, except in those cases where a new party inherits both the plants and the requisite zeal.
If you really care about plants, as opposed to caring merely about your personal relations to them, consider what will happen to your collection. Who will inherit your plants? The county dump? Black-thumbed Uncle Fred? Ancient Aunt Belle?
My own aim has been to distribute cuttings or seedlings of everything I grow. I send out seeds of anything rare to two or three virtuosos, so that nothing is grown only by me. I do not expect that anyone else would be nutty enough to wish to adopt the totality of what I grow, but the whole thing could be reassembled if need be.
As long as people care about plants, mesembs will attract interest by their beautifully bizarre and highly individual properties. The best cultivation methods express those qualities; indifferent ones reduce them all to a grey-green sameness.
The reader should bear in mind that the timings I give are those which work for me. These mostly correspond to the behavior of populations in habitat, but in other horticultural ambiences things are not so directly transferable. If a different timing is working well for you, ignore all my advice.
Generic names and concepts are still very much in flux, and this fluidity is unlikely to cease soon. Also, it is extremely difficult to identify many species, particularly those in charmless genera like Aridaria. Of the species mentioned here, I have seen most of the types and am still plagued by some uncertainties, but most of these names are well-understood in horticulture. With any luck they will outlive all current labels. And speaking of labels: it is amazing how much a uniform and freshly made set of labels improves the look and sense of a collection.
A word about how to arrange plants in your collection. My own are randomly placed, as this helps to prevent pollination accidents, but it is usually more satisfying to have all members of a genus together, and it certainly makes comparisons easier. If you have the room it is better to allow at least a few inches between pots; the plants will grow in a more even manner.
A small genus of tufted or mat-forming species, most having dark green pointed leaves with terminal teeth. They naturally grow and flower in late winter but are easily convertible to summer, or indeed to continuous, growth. Acrodons can be neglected for months and will bear no permanent grudge, but they prefer frequent watering. The flowers are uniquely beautiful; the petals have very fine marginal stripes of brownish-carmine. So far I have failed to hybridize Acrodon with anything, not even with the obvious candidate, Marlothistella.
An annual with pinnate leaves, A. pinnatifidum is lovely while it lasts. It is best sown in winter and treated like early lettuce.
Several not quite congruent species comprise this genus, which has been shifty since its inception. Some, those in the warted A. luckhoffii group, behave like the winter-loving titanopsis and should perhaps be placed with them; some having smoother leaves (A. loganii, A. rosulata, A. spathulata, A. schooneesii) are quite hardy and favor spring growth; and some have now been (re-)placed in Deilanthe, q.v. All these species tend to have fat roots and need good winter light for their best behavior. Their summer activities are usually minimal, though European growers will report a different story. They are universally prone to red spider, mealies, and root rot. Hybrids with Deilanthe, Nananthus and Titanopsis are easily made, horticulturally desirable, and taxonomically problematic.
Probably a synonym of Eberlanzia, q.v.
Note: Hartmann 1993, erroneously considerd Amphibolia to be a synonym of Eberlanzia. She now lists four species of Amphibolia. Illustrated Handbook of Succulent Plants, 2001, p. 37.
Now renamed Drosanthemopsis Rauschert, q.v.
Note: Drosanthemopsis now = Jacobsenia, Illustrated Handbook of Succulent Plants 2001. page 40.
The sole species, A. fissoides, forms compact tufts of finger-like uniformly dull green leaves, rarely with livelier red keels. The plants sleep all summer when the fingers will be quite wrinkled. New growth requires generous watering from fall until early spring. The plants are most outstanding for their large purple flowers produced in late winter. Hybridizes reluctantly with Didymaotus.
A recently revived and revamped segregate from Ruschia (which was far too diverse), Antimima is horticulturally variable. Fortunately, the only species of great pot-interest are the dwarfs, e.g., those in section Microphylla (Brown's ms.genus “Brachyphytum”), which sheath and behave like minute Cheiridopsis, being inert in summer and thirsty in winter. The type of the genus, A. dualis, is very beautiful when raised in good light, and it behaves like an argyroderma. The related “A. argentea” is also most attractive. “A. ventricosa” has huge bicolored flowers but it requires good winter light and much food to flower well. It dries out very quickly. Another group of antimimas resembles Astridia except for the shorter five-bunched petals and small seeds. These species prefer to grow in winter but are large and non-fussy. All antimimas (pronounced as in Aunt Jemima's) have large closing bodies in their fruits and they mostly flower before spring. “Antimima lawsonii” from chilly Campbell flowers in spring, and, like “A. pumila” from near Calvinia, must be quite hardy.
Note: Antimima argentea, A. dualis, A. lawsonii, A. pumila and A. ventricosa are all listed by Hartmann. Illustrated Handbook of Succulent Plants 2001.
South Cape annuals of which I have no experience, alas.
A. cordifolia is a familiar pot plant and ground cover. It is very easy to grow; almost too easy, as it becomes invasive both by spreading and by selfing. But it can be dwarfed in a four-inch pot and it looks good in a hanging basket. All aptenias (three or four species are known) behave like water-loving garden annuals, though they are in fact perennial.
A genus with a single very distinct species, A. pillansii. It is an inconspicuous but interesting shrublet with blackish-green leaves so sticky that they are usually coated with whatever detritus is nearby. It grows and blooms in winter, when it enjoys water. In summer it needs little water—and no, you cannot wash off the sandy coating.
Note: Hartmann lists a further three species. Illustrated Handbook of Succulent Plants 2001. p. 68.
A genus of ten species and several dozen microvariants, Argyroderma is uniform as regards cultural requirements. The earlier in summer they are watered the better: treat them exactly like lithops and all will be well. Nothing is gained by a summer drought: natural or not, this merely kills the roots and shrinks the buds. The great fear with “argies” is that their leaves will crack like old china. With steady yet light summer and fall watering, and a slow drying off post-flowering, this is not an issue except in one respect: never water them during rainy weather! A further warning: never soak them.
Well-established argyrodermas resent repotting, so it is best to keep them in mabel-mix for five years or even more. They do not mind salt in the least and most species do not divide heavily, so repotting is only necessary when the (clay) pot crumbles. Sown in mid-summer, argies can flower just a year later.
The sole long-leaved species, A. fissum, forms large uneven mats and can be pruned to keep it in bounds, or one can grow the Klawer form, which is short-leaved and compact. However some of the larger forms have superb flowers in many shades including true carmine and a ripe tomato red. The remaining species have more or less rounded leaves. Some wild populations have a marvelous and unique range of hues and rare combinations (inner yellow, outer brick red or purple, or vice-versa) and it is interesting to replicate these in cultivation. A. testiculare has stupendous multiseriate flowers like magenta crepe.
Note: The addition of Argyroderma theartii makes a total of eleven species. Hartmann, The Illustrated Handbook of Succulent Plants 2001, p. 71.
This nothogenus was based on a mysterious hybrid made by Dr. M. Morgan. When described by Kimnach (1980) its parentage was unknown, but I have finally cracked its code. Almost certainly it involved Argyroderma delaetii × Lithops divergens var. amethystina. My hybrids are identical to Morgan's, even sharing its habits: slyly pupping, producing lopsided flowers, and turning an alarming pink in summer's heat. Most other attempts have merely selfed the would-be parents. Very recently I crossed A. delaetii and L. verruculosa. In this case I have some faith because the flowers of A. delaetii died in such a quick and promising manner.
A big or little (post-reduction) (sub)genus of shrublets with long half-leafless shoots. Mostly winter-active, but not at all fussy. Many plants will drop most of their leaves half the year, or periodically throughout the year. Some species are attractive in rockeries, where their long stems can wave in the breeze like dieramas and their large nocturnal flowers can be enjoyed by passersby. Some are probably fairly hardy but to my knowledge they are untested.
Note: Reduced to four species Hartmann, Illustrated Handbook of Succulent Plants, 2001, p. 75.
Though A. amplectens covers whole hills in the Richtersveld, it is almost unknown in horticulture, and I have never managed to collect viable seeds. The leaves have a certain dactylopsian aspect but they are borne on upright stems.
Several species comprise this unpopular but attractive genus of shrubs. Most of them are a bit unwieldy in pots; for me, their wonderful flowers justify the space. They are also handsome as seedlings. All astridias grow in winter, which is also when they tend to flower, though their production is erratic. They do best in large pots and rather rich soil.
A small genus of tufted plants with grassy sharp-angled leaves. They look much better in rockeries than they do in pots and when given free root-run will flower profusely all summer. They are essentially summer growers. Some of the smaller species, e.g., B. jamesii, are attractively glaucous and stay compact. They are probably deeply hardy to judge from their habitats. Under glass, all species are prone to spider mite if kept too dry in winter.
Now placed in Conophytum, as C. khamiesbergense, Berrisfordia seems rather distinct on behavioral and horticultural grounds, since it flowers in spring from new leaf-pairs surrounded by still-active old ones. The plants like a very acid soil, copious water, and shade in the afternoon: I usually place the pots due east of taller pots. If the fissure walls puff up to watery blisters you are an overwaterer. Avoid summer heat! Some clones are far more attractive than others, bearing extra teeth and purple pigments, so it is good to raise a large batch of seedlings and select out several beauties. This will also allow one to select for vigor, since individuals vary greatly in this respect as well. C. khamiesbergense is sometimes self-fertile and is difficult to hybridize with other species. However, it would be worthwhile to apply its pollen to other conophytums.
A tiny genus of two attractive species. The well-known B. cana can take a fair amount of water when in fresh growth. Most active in early fall, when it sends out new leaves and flowers, it needs much light to stay compact and properly asymmetrical. Otherwise it grows too lax and “turns into” the second species, B. tugwelliae (L. Bolus) S.A. Hammer, comb.nov.(5) This one has paddle-shaped erect leaves and is never compact, so do not attempt to starve it into prostrate submission. Both species have attractive glossy petals the color of egg yolks. Pronounced Bay-lee-ah, by the way.
5 Bijlia tugwelliae (L. Bolus) S.A. Hammer, comb.nov. Basionym: Mesembryanthemum tugwelliae L. Bolus in Ann.Bol.Herb. 1(3):129(1915). Type: “Prince Albert,” Anna M. Tugwell s.n. (BOL). Selected specimen: S. Hammer 1167, “Cape Province: 3 kilometers west of Prince Albert,” 10 August 1992 (HNT).
A small genus of diverse habits: creepers or upright shrublets. The leaves are connate and attractively alabastrine or finely fuzzy, and the flowers are outstanding. Braunsias grow primarily in winter and flower in winter to spring. They thrive in poor soil and are not very particular about food and drink. However, B. geminata dries out quickly, and the rarest and most beautiful species, B. vanrensburgii, is always thirsty.
A genus of a dozen species, only a few of which have reached or survived cultivation. Those known to me do best with heavy watering in late winter and spring; by summer the ephemeral leaves die away, leaving the beaded joints and fringed collars exposed. I place the dormant plants under the bench all summer; there is no point in stressing them.
A lost genus. All one can say about its cultivation is that a few plants survived Haworth's inspection and at least two plants persisted into the 1950's, so it was apparently not a difficult genus. There is no clue as to where the plants originated except that it must have been the southern coastal regions. A pity: from Haworth's account the large red flowers sound beautiful. Hesselbarth's photograph of C. teretiusculum in Jacobsen's Lexicon is apparently authentic and is in any case worth some contemplation.
A lovely annual with bright golden flowers, C. pomeridiana can be treated like an “ordinary” non-succulent garden annual. It will thrive in a big pot.
This genus includes the landslide-inducers familiar to southern Californians. Cultivating carpobrotus in a pot would be about the same as raising a shark in a bath tub. They need Lebensraum and when given it will produce huge flowers; C. quadrifidus is especially lavish. All species will grow whenever they are watered and they will wait patiently whenever they are not.
Two very similar species are known: C. ringens and C. peersii (the latter was the basis for the redundant genus Tischleria Schwantes). However, some beautifully glossy plants in old European collections look unlike the two species as I know them from the field and from cultivation here. Carruanthus are very easily grown; indeed if not kept pot-bound they become rather weedy. They are dormant whenever you please, but I treat them as spring growers. In any case they flower abundantly in spring and summer. A pink-flowering freak is preserved at the Bolus Herbarium, but in cultivation only the usual yellow forms are known. Carruanthus ringens hybridizes with Machairophyllum albidum (as reported by Haworth!).
Note: The true Carruanthus peersii has only recently been re-discovered and is probably not yet in general cultivation. The pictures and habitat notes in Mesembs of the World are incorrect. Both plants shown including the ones labeled C. peersii are of C. ringens. C. ringens grows in full sun and has toothed leaves while the true C. peersii grows in shaded kloofs and does not have teeth or at least very rudimentary teeth on its leaves. C. peersii also has smaller more cup-shaped flowers. Mesemb Study Group Bulletin 19/1, 2004, p18. with pictures of both.
I know this only from its description and have only grown a hybrid, Caryotophora × Skiatophytum. But the cultivation of C. skiatophytoides has been successful when the clay-potted plants are kept on water-filled metal trays. The species is not very succulent.
A large genus with diverse habits. Almost all the species have very attractive flowers and some of them are variable in color within populations. But alas, the most spectacular species are lousy pot-plants — they are too massive or they wander invasively — and the compact species tend to have plain vanilla flowers. However, C. subulatoides is a fine and easily flowered pot-plant, and C. spissum is also good if enough light is available to induce its subtly shaded flowers. C. alstonii needs a large pot and good light, but its flowers are so very beautiful — they have the vibrant color of scarlet anemones — that it deserves prime space. Cephalophyllums grow in fall and winter and enjoy ample water at this time. In summer the old leaves will shrivel slightly. A few intrageneric hybrids have been made in Japan and elsewhere; an obvious and worthy goal is to reconcile compactness and floral delight.
A small genus of two species. C. “albiflora” flowers generously in autumn and its crispate yellowish-green leaves are attractive throughout the year. The magenta-flowered C. pachyphylla flowers in winter or spring and comes in narrow- and wide-petalled forms. All forms are very easily grown. Inert in summer, they require irregular watering in fall and winter; new leaves emerge prematurely and rudely if the plants are fed too early. Older leaves are apt to darken to black and though no-one knows quite what causes this, it seems natural and harmless as a blush. The flowers are often borne in threes and last for several weeks.
Note: Hartmann lists four species in the Handbook 2001.
A genus of several species, some of them hardly known. The dominant species of horticulture, C. musculinum, is extremely hardy and makes an excellent plant for a rockery or an unheated greenhouse. In a pot it needs periodic flooding, and in a heated house it will grow essentially year-round, with a floral peak in late summer. All known species are extremely prone to red spider, so they should be misted often.
A mid-sized genus of about 35 species which are diverse, interesting, and half-ignored in cultivation because of their unfortunate tendency to misbehave in poor light. The leaves of all species stretch heavenwards, those of dimorphic species become tri- or monomorphic, and many species entirely fail to flower. Some species, e.g., C. purpurea and C. speciosa (which includes the delightful C. splendens, with its sinuate margins and orange flowers), flower in fall and thus escape the short-day curse. The proper dimorphs like C. meyeri and C. peculiaris need strong winter light to do well; try a warm high shelf for these. C. delphinoides flowers very late in winter and it might be possible to delay its growth until winter's gloom recedes. When active, the small species need frequent light watering; the large ones, like C. denticulata, prefer irregular drenchings. The lame duck leaves of most species are inevitably unattractive, and you may find that some plants will jettison entire fruit-bearing branches. All species are torpid in summer, but watering at the end of summer may wake them early, to their benefit. Very easy from seed, which germinates within four days, except for C. pearsonii, which is thrice as slow. Certain hybrids within the genus are attractive and easily accomplished (e.g., C. purpurea × C. aspera, C. schlechteri × C. speciosa, and C. robusta × C. purpurea); it is also possible to hybridize Cheiridopsis with Odontophorus and Ihlenfeldtia.
If we had any material we might know how to grow this supposedly extinct and certainly striking yellow-flowered relative of Erepsia. To date, all searches in the vicinity of Villiersdorp and Tulbagh Kloof have failed.
A tiny genus of annuals, unimportant for cultivation (they cannot vie with the showiest Dorotheanthus species).
A tiny genus of strange plants which hardly seem to belong in Mesembryanthema until one sees their flowers. They are not happy pot plants in dry climates, requiring a risky daily watering. But the flowers are rewarding and it is worthwhile to sow a few seeds in a large pot of sandy soil and see what happens. The subgenus (formerly the genus) Herrea, with its persistent tap root, is better suited to arid cultivation.
Thanks to the increased popularity of Conophytum, the collective conosciousness has been raised and everyone has realized that these dwarfs need a lot of water! On a recent autumn trip to Europe I was surprised to see several expert growers watering their plants just as often as I do in New Mexico. I'd thought that my arid air had necessitated this frequency but I should have recalled that the most difficult species, C. rugosum, often grows near winterbournes (water courses that run only in winter. Updateing editor).
It is no surprise that many species grow so well in dank greenhouses: they are adapted to shady, moisture-trapping crevices. However, a balance must be achieved between a cool situation in which the plants are evenly moist and one in which they receive enough warm sunshine and near-dryness to bring out their finest contours and colors. The more sun, the shorter the internodes, the more compactly attractive the plants, and the greater the danger of desiccation.
In fall and winter conophytums like subtle but constant moisture. In early fall this may mean watering at least twice a week and in some cases it means daily watering! In any case, frequent shallow watering produces the best results, Of course the instruction “keep evenly moist” is, like Nixon's perpetual five o'clock shadow, somewhat paradoxical; one can but try. Winter botrytis is a danger in humid conditions: growers must cut away spent flowers before they are attacked by it, as the floral tube can become a fatal conduit into the plant's heart.
At a certain point in late winter the roots stop accepting water, and the tissue of the current leaf-pairs starts to collapse. This is your cue to withhold water. Plants entering dormancy often shrink alarmingly. Once the resting sheaths are properly formed, the large-bodied species can be left quite dry; the smaller, more delicate species will appreciate light weekly refreshment. If the leaf-tips pop out prematurely (i.e., in early spring), this is no disaster, but remember that premature exposure invites burning unless the plants are watered frequently. You may well find that many conos will behave exactly like your lithops.
As the popular song tells us, breaking up is hard to do, but large older clusters are better off divided. You can retain and reroot substantial chunks of a mature plant and subdivide the rest. This is best done soon after the plant flowers.
Raising the genus from seed to seed is the best way to understand it. I sow most species in early fall but a few certainly grow better if sown in mid-summer (e.g., C. burgeri and C. ratum) and more should be tested for their summer suitability. I have the worst results with spring sowings: the young plantlets start out confidently but then they confront a blast of heat before they can prepare for it. Born into moist heat, they would have a better chance of adapting.
An obscure but newly revived small genus from the coastal belt of the southern Cape, consisting of a few species with fat tufted leaves and a few others with long internodes. They are oddly attractive in a rockery but are probably not hardy. C. taylorii is rather charming and certainly indestructible under glass. All species are summer growers but they will also respond to winter moisture. The flowers have curious washed-out pastel shades.
Note: Hartmann now lists seven species in the Handbook 2001.
A small genus of several species, some poorly known at present (C. hallii is lost). The smaller species are attractive pot plants; the others are better off in a rockery where they will reach a yard across. A few populations have a strange epidermis which almost seems to exude crystalline papillae. Inert for much of the year (though they would probably grow year-round if I pushed them), cylindrophyllums wake up in fall, add a few cylindric leaves to their existing tufts, and then produce beautiful flowers in spring. These are large and yet delicate, whitish to raw butter yellow with hints of orange and scarlet.
The famous D. digitata is difficult for many growers and the scarcity of viable seed hasn't helped with experimentation. The species is the subject of various myths. For example, it has been widely reported that salt helps it prepare for summer sleep; but the plants collapse into equally mushy dormant heaps whatever you do. Most active from late autumn until late spring, it should be kept constantly turgid during this period. It needs sunlight to look good.
D. littlewoodii recently re-entered cultivation. It will be a better pot subject than its larger brother. The three young clones in my care (one raised from seeds nearly twenty years old!) have behaved nicely and have produced a few seeds already.
Pollination of both species is best attempted with a fine filament before the flowers reach their maximum width, i.e., within four days of anthesis; otherwise the tube is blocked by hardening nectar (at least, that is the case in my aridarium). Seeds should be sown in summer. It is best to use large pots and mabel-mix with extra pumice. Sow seeds thinly. Two-year-old plants of both species can flower.
Note: Although Hartmann subsumed this under Phyllobolus but it has be reinstated. See Pascale Chesselet's Interactive Mesemb Database.
A newly revamped small genus of three species, only one of which, D. peersii, obeys the generic name by flowering in the evening. This is also the most widespread species and, as Aloinopsis peersii, is a familiar pot plant. All species have huge roots and felted straplike leaves. They are very active in late winter, when they produce their wonderful flowers smelling of primrose or honey. By spring the year's quota of new leaves has been filled and the plants need only light refreshment until fall. My intrageneric hybrids tend toward wide pink variegation, and one intergeneric hybrid (D. thudichumii × Aloinopsis loganii) is a charming reduction of its mother.
Delosperma is a large genus with varied requirements, but most species are summer-active and can be treated almost like subtropicals. The species with tuberous roots (like D. sutherlandii) should be kept quite dry all winter; you can even lift the roots and store them as you would dahlias. Many species are extremely hardy and flower better when exposed to cold. Indeed, flowers are the great thing about the delospermas: they come in the full iridescent range of mesemb colors and there are even some species with pubescent petals.
Some species are self-fertile, like D. sphalmanthoides, which is an excellent and super-hardy rockery subject. The wonderful D. longipes, with its huge tubers, recently entered cultivation and I hope to tame it and its tubers soon. D. dyeri is lost and deserves a thorough search around Tarkastad and Hogsback: its shining red-orange flowers would grace any collection. For hanging baskets I recommend D. vinaceum, which has splendid burgundy flowers with hearts of rose. Many other desirable species are known only from their flattened representatives in herbaria. As for hybrids: all my many attempts have failed except for Glottiphyllum “album” × D. echinatum. Within Delosperma, barriers are surprisingly strong.
Note: D. dyeri is listed by Hartmann as extant with a provenance of Alice, East Cape, Sth Africa. However D. longipes is placed under Drosanthemum longipes. The genera Corpuscularia and Hartmanthus have also been separated from this genus. Hartmann, The Illustrated Handbook of Succulent Plants, 2001. It is likely we will see further changes to this genus.
There are two groups within this modest genus: those with tiny leaves and wispy non-closing flowers, and those which resemble the showier monilarias. Both groups differ from the related Monilaria in that their sequences are at least mildly indeterminate; they will grow continuously throughout winter, making more and more leaf-pairs. The small-leaved dicrocaulons are the last to go, and when they do go, they look dead. Their dormant connate leaves are tiny, concealed at the ends of the stems, while those of monilarias are swollen, palpably waiting.
All species require lots of water from fall until spring, until they actually collapse. The wispy-flowered species are difficult to pollinate; it might be wise to give them over to a friendly bee. The large-flowered species are difficult to flower in weak light. However, their flowers are spectacular; some open white and quickly change to an indescribably rich shell pink.
A familiar monospecific genus. Most collectors seem to think it better to have loved and lost it than not to have loved at all, but with proper treatment Didymaotus lapidiformis will thrive for decades. The plant loves a heavy clay soil; it grows badly when given the stimulus of humus, which is to Didymaotus as Ritalin is to chickens. It requires as much sun as you can muster and enough water to make its root system really active; the roots are rather thick and will quickly reach the bottom of a four-inch pot. With adults, do not think of watering the main body: rather you should imagine that you are watering and sustaining the small twinned side shoots which are visible during all of the active season. Occasionally a plant will start to produce bouquets: one pair of bracts can support five to seven pairs of bracteoles!
Plants go dormant after flowering, shrivelling a bit and turning greyer from wax depositions. During summer I water perhaps twice a month, enough to prevent gross shrivelling.
The leaves of seedlings are pointed and seem uncharacteristic, but if the light is sufficient, the adult form will be achieved after four or five moltings. (Otherwise retrograde growth is guaranteed.) Didymaotus will sometimes hybridize with the related Antegibbaeum, but pollen of the latter is more likely to induce selfing.
Adult plants of this genus behave like lithops: summer expansion leading to flowering in fall, followed by a slow transfer of resources in winter; the main difference is that the presence of two active leaf-pairs is not unusual in some Dinteranthus. The plants require slightly less water than do most lithops . Excellent drainage is essential, as all dinteranthus are somewhat prone to rot, D. microspermus subsp. puberulus being the most resistant of the six taxa. I give them all extra pumice; for older plants I use at least 50% pumice (both fine and coarse grades). Their nutritive requirements are amazingly modest and the root systems of even the healthiest plants are minuscule. What they need most critically is good light, which will give them a bone-white aspect. Older long-stemmed plants can and usually should be turned into cuttings and re-rooted.
The real trouble with dinteranthus is that the seedlings are so tiny that they are apt to damp off. But if the following rules are observed, success is likely. Sow in high summer; use sterilized soil with extra grit and enough peat to ensure high acidity; do not cover the seeds. Place the sown pot in a water bath, cover the whole assemblage with clear plastic and place it outdoors in a bright spot. Wait three full days, remove the pots to your usual place of germination and mist them at least twice a day. Seedlings should be evident within twelve days of sowing; they are extremely small at first and resemble green crystalline raspberries. The object is to induce them to grow as rapidly as possible. I f this takes daily mist-feeding, then do it. B y mid-autumn the cotyledons should turn greyish-white from a calcium deposition which strengthens them. After this whitening the fissure walls part and the true leaves are visible through the resultant peephole. Thereafter you are home free: treat the seedlings like young lithops. Delay transplanting until the second set of true leaves is fully formed.
Various interspecific hybrids are possible in Dinteranthus but they are not very interesting, and the most obvious and desirable Don Juan, D. pole-evansii, is recalcitrant. However, ×Dinterops (Dinteranthus × Lithops) is quite attractive and the second generation grex is even better. More attempts should be made: especially crosses between D. vanzylii and the albinistic lithops.
A very small genus, fascinating aesthetically and biologically. Here the Mitrophyllinae reaches its ultimate meltdown: not only do the plants go intransigently dormant, they retreat to an underground organ like a hard-shelled pea. The genus comprises two species, one of which, D. luckhoffii, has distinct forms with short or long pedicels.
When in active growth from late autumn to early spring, the plants can take strong light and unbelievable quantities of water. The epidermis should be maintained at a high gloss. Loss of turgor is quickly made evident by a kind of spongy dullness, but the plants easily recover from slight losses. They are very readily bruised, so handle them gently. Sown in summer, D. luckhoffii can flower six months later. D. retroversum, however, takes at least eighteen months to flower, probably because of the peculiar sidelong fusion of its mature flower-bearing leaf-pairs. Both species are self-fertile when happy. The plants are short-lived: after ten years or so they will peter out no matter what you do. At least that has always been the case for me: certain older plants go dormant in the normal manner but the next fall, no-one is at home. They last longer if grown in a heavy clay mix.
A small genus of large coastal creepers, best suited to Malibu and environs. The Australian species are not well-known in “western” cultivation. D. dunsdonii, a charming ruddy dwarf from the limestone belt around Bredasdorp, South Africa, makes a good pot subject. Like all disphymas, it can accept water year-around. Self-fertility is common in this genus.
Note: Hartmann also lists the two New Zealand species in The Handbook, 2001.
Beautiful ephemerals which are much neglected by growers who fancy permanence. But just think: they never need repotting. If sown in mid-winter they bloom in early spring. They can even flower throughout a cool summer, but here in Little Hades I have rarely managed to keep them alive past June. They are extremely easy to grow, given full sun, a sandy soil, and frequent watering. Some hybrids have been reported but I have had no success repeating them.
A small and poorly known but attractive genus from southern Namibia and the adjacent parts of South Africa. All species (be they two, four, or more) have fat white to bluish leaves, sometimes with teeth and irregular prominences. For me they are most active from late winter until later spring. They prefer a very bright and arid situation, tolerate heat far better than cold, are rot-prone, and seem very sensitive to an excess of potassium. It is difficult to root dracophilus from cuttings and generally pointless as well, so quick are they from seed. The flowers are open from dusk until dawn and are extremely attractive. They can readily be pollinated by Juttadinteria.
An awkward genus which is currently monotypic. It is probably best placed in Jacobsenia, though it is also related to certain species currently placed in Drosanthemum, like D. subalbum. Drosanthemopsis salaria is a fat-leaved shrub. Its uniquely complex whitish epidermal papillae are best admired with a good lens. The whole plant has a strange felted look and it is fascinating to observe freshly watered leaves: the surface is a wick. The off-white flowers appear in mid-winter but they are neither very attractive nor easily induced. The plants grow best in a heavy clayish soil; water heavily but irregularly from fall until spring and mist frequently through the year.
Note: Both D. salaria and D. vaginata are now Jacobsenia vaginata. Hartmann, The Illustrated Handbook of Succulent Plants 2001, p. 226.
A widespread, complex, and interesting genus poorly represented on paper and in collections. There are three basic growth forms: upright shrubs (some having glossy brown trunks with white streaks); compact globose shrublets; gross or delicate creepers. Many species have outstanding flowers, D. speciosum being famous for its brilliant displays of lava and scarlet. At the Karoo Garden we once made a bouquet of D. speciosum variants and came up with at least a dozen glowing colors. Drosanthemums are easily grown given large pots and periodic floods. Most species seem very active in early spring but they are capable of continual growth. Once a year (usually in fall) I prune them back severely.
Note: I expect to see changes to this genus.
A genus which has recently undergone such extensive renovations and modifications that its understanding in horticulture, and its scientific meaning, are completely at variance. No longer can we look at a spiny ruschia-like shrub and say: Eberlanzia! But for strictly horticultural purposes all the “eberlanzias” can be treated together; they are tough customers and do best with large pots, strong sun, and occasional privations. The spines are fierce and should be treated with respectful caution. The nicest “eberlanzias” actually belong to Leipoldtia and Antimima (A. hantamensis) but they are hardly known in horticulture.
Note: Many species especially those with many fierce spines are now placed in Ruschia. Hartmann & Stuber 1993. See The Handbook 2001, p. 251.
A small genus with a big distribution: from Kimberley in the northern Cape, to the Sperrgebiet and the Windhoek highlands in Namibia. Regardless of provenance, all species are most active from late winter to early spring. The plants are very prone to red spider, and because of their large taproots, somewhat prone to rot and mealies. The Sperrgebiet species, E. derenbergiana, is a quick grower and can make substantial mats in a few years given a large pan, or one can maintain it as an attractive bonsai subject. It grows in pure coarse sand (!) in habitat and has beautiful flowers, white to vivid pink. The true E. montis-moltkei, with its twisting blade-thin leaves, is really curious and attractive; the bogus “E. montis-moltkei” of horticulture is actually the Yemenese form of Delosperma harazianum, the easy self-fertility of which has insured its spread in cultivation.
A practically unknown monospecific genus, recently rediscovered in the Hogsback Mountains north of Grahamstown. E. alpina is an absurdly minute plant which resembles a red-leaved delosperma. It seems to need ample water and is apparently self-fertile.
The sole species, E. octonaria, is an ungainly shrub with splendid flowers. It will bloom in a four-inch pot but requires much water and a fair amount of pruning to do so. At least a few longer branches should be retained, as these are the ones which will produce buds. Coming from the western Richtersveld, it is a winter grower; in summer it requires just enough water to prevent desiccation.
Erepsias are summer-growing shrubs which are not very succulent. They are on the interesting side of beautiful but their flowers are in some cases spectacular (those of E. saturata are blackish-carmine) or bizarre (E. aspera has an icicled gynoecium and thread-like petals), and they are borne over a long period in summer. The larger species, like E. (Semnanthe) serrata are easier to manage in dry climates and they bear very good flowers. Treat all species like aquaholic lampranthus. They are apt to die back at the leaf-tips and are somewhat prone to red spider, so mist them often.
Note: this genus now includes species such as Kensitia pillansii and Semnanthe lacera both well known to older mesemb growers.
As its name implies, E. alpina headed for the hills and it suffers from a common problem of alpines: intolerance of heat. In habitat it often grows in shade and in the greenhouse it does best in dappled light. It needs copious water year-round and with luck it will flower in late spring.
A wonderful genus for beginners, more diverse than most collectors realize. Not all species are toothy or mottled, and white flowers occur in at least two (some flowers are even pink). All species are active in summer and torpid in winter. Some of the newer (re-)introductions (like F. hooleae, a neat dwarf) are not as easy to grow as the fearless F. tigrina and should therefore be treated a bit cautiously, with periodic droughts; they easily lose their roots and are prone to a stem rot which is invariably fatal. If the leaves suddenly soften, the plant should be burned on a funeral pyre. It is very difficult to hybridize faucarias with anything outside their genus, but there is one apparent and certainly weird hybrid with Rabiea. Within Faucaria there are no barriers at all and much of the material in gardens represent a mixed bestiary. F. tigrina and F. felina should not have the bizarre caruncles of F. tuberculosa, F. subintegra should not have tiger stripes, etc.
Note: F. hooleae = F. gratiae, Hartmann in The Handbook 2001.
This genus causes problems for people who try to make its species look “natural”, i.e., with eye-like tips peeping out from a drift of sand. This can be achieved in cultivation but requires a shallow tray, a very bright situation, and lean soil. Do not try pure sand, it won't work; rather use loam leavened with grit or pumice. Nitrogen causes fenestrarias to expand alarmingly, and excess water causes their tiptoes to crack badly, like potter's fingers.
Both subspecies are most active in early fall to late winter. During this period I mist them on all bright days. The roots are actually quite fat and require some special care: water the plants from the bottom once or twice in fall. The flowers appear in fall and are white to chrome, or orange with pink streaks. After the flower spree, reduce watering to a minimum, just enough to keep the roots turgid. 'Fireworth' is a fine strain accidentally developed or perpetuated by Ernest Hepworth; its flowers are nearly red. Various hybrids between the subspecies have given a range of pastels and I am now working on a strain which is super-floriferous.
A difficult genus under some regimes. F. pulchra subsp. pulchra needs an acid, very well drained, preferably quartzitic soil, and acid water. Given these conditions it can be watered every day all summer long and will astound you with its flowers. It will grow in alkaline soil for a few years but will not thrive. Healthy older clusters can be divided and re-rooted though it is better to sow more seeds. The periscope effect achieved by planting frithias with their windowed tips at soil level never lasts. If you have alkaline conditions, grow F. pulchra subsp. occidentalis H.E.K. Hartmann & S.A. Hammer, ined. (this name replaces the invalid var. minor De Boer), which readily accepts a high pH. Its pale flowers are not quite so spectacular as those of subsp. pulchra but they are charming and freely produced.
Pollinating frithias is like dipping for water in a deep well, the bottom of which you cannot see. The “well” (corolla tube) is about an inch deep and the hidden stigmas are somewhat brittle. Hybrids between the subspecies give rise to very interesting colors including orange; picotee effects are also common.
Note: F. pulchra subsp. pulchra is now simply F. pulchra while F. pulchra subsp. occidentalis is now Frithia humilis Burgoyne 2000.
Though much ink has been spilled on the requirements of this genus, the species are actually quite easy to grow. They are all active in winter; the main point of divergence is the flowering times. Some species flower before the winter solstice, but most flower after it, and buds will appear as the days grow longer. These species must be watered well to sustain their buds. Some four months before the flowers open in late spring, G. album reveals its buds; they resemble the white angular bodies in miniature. This is the last species to flower.
No gibbaeum moves in the summer. Nonetheless, the non-sheathing species require some sustenance then, enough to prevent obvious furrows in the leaves. G. album should be closely watched; if the heads have the not-wearing-dentures look, the plant is too dry, but it should not be watered so heavily that the fissures are forced open. The sheathing species are obvious about their needs: from spring until fall they are all wrapped up and require no more than an occasional misting. The exceptional species is G. nebrownii, which should be forcibly wakened by late summer (see Imitaria); the visually similar G. nuciforme slumbers on until mid-autumn. G. austricola Glen, nom.prov., the southernmost species, comes from the wet Swellendam region and requires much water. In contrast, the sphaeroid gibbaeums are highly sensitive to excess water and it is difficult to persuade them to absorb their old leaves neatly. Some of the velvet-skinned species are prone to sunken spots and patches of weird papery dryness. I do not know the cause, only the scarred effect.
Within Gibbaeum, many species can be hybridized, but so far nothing of great horticultural interest has resulted. A hybrid with Glottiphyllum, however, has outstanding flowers of a soft salmon red, often striped with orange or pink. This hybrid (×Gibbaeophyllum) has appeared several times in cultivation but I suspect it to be of wild origin.
Note: G. austricolum = G. haaglenii H.E.K. Hartmann. Also a new species G. johnstonii is listed in Hartmann; The illustrated Handbook of Succulent Plants 2001.
The denizens of Animal Farm never saw a dead donkey, and few of us have seen a dead glottiphyllum. But how many have seen a really well-grown one? Actually there are two ways to grow “glotts.” The first is to let nature take her course, which means giving them large pots and copious water; they will burgeon into enormous masses of glistening green or ruby jello. The other is to starve them into svelteness by hot summer droughts, small pots, and firm loam. The results can be very attractive. A few species and forms are naturally compact: G. neilii (thick pewter-grey leaves) and G. pygmaeum (a dwarf form of G. nelii, often confused with G. neilii). In any case it is best to treat all species as late winter growers. The species hybridize readily and they are sometimes self-fertile. G. “album” is currently very rare but it has given me some seedlings via fenestraria pollen. The lost G. rubrostigma had the quality one would expect and its habitat (Prince Albert) deserves a thorough search.
Note: G. “album” has been used for different species with white flowers. G. “pygmaeum” is merely a dwarf from of G. nelii. G. rubrostigma = G. surrectum. Hartmann, The illustrated Handbook of Succulent Plants 2001.
A charming but space-consuming monospecific genus, with rhombic leaves and wiry reddish stems. It looks very good in hanging baskets or rockeries but is piggish in pots. The flowers come in several shades of pink. Basically a winter grower, it is probably somewhat hardy, as it is very widespread and reaches areas which experience at least mild frost.
Two ex-delospermas necessitated this minor genus from the northern Richtersveld and the adjacent parts of Namibia. The species are easy to grow, tolerating drought and dampness and preferring an erratic oscillation between the two. H. hallii is the better species to grow, being more compact in habit and more beautiful in flower. Like H. pergamentacea, it is most active in late winter and shows little or no growth in summer.
Note: H. pergamentaceus according to Hartmann, in The Handbook 2001.
A confused genus of far too many species. Regardless of name or provenance they mostly behave alike under glass, flowering from late winter to spring and adding leaves for most of the year. They are very easy to grow. Many species are probably quite hardy and those from the Great Karoo, like H. stanfordiae, should be tested.
Now placed in Conophytum, as C. herreanthus. It is a very easily grown species with whitish, widely diverging, sharp-pointed leaves. Because the old leaves cannot form sheaths, the new ones are exposed to sun all summer, when the plant should be given enough water to prevent gross wrinkling but not enough to activate the plants. C. herreanthus subsp. rex has rose-pink flowers and its leaves are beautifully edged in red.
I have never been able to germinate either of the species in this genus, which is a pity; they are very attractive in habitat, and most peculiar.
A small genus of three to five species (only two are recognized at present), all well worth growing for their sharp-bladed leaves and superb flowers. Those are usually a deep golden yellow, but several pastel shades are found, and some exceptional variants of I. excavata (I. “vanbredai”) have dark pink flowers with lilac grey pollen. Easily grown if given sufficient light, all ihlenfeldtias prefer mabel-mix. They are active in fall and winter, flowering in early spring.
Note: These species were formerly placed in Cheiridopsis. Ihlenfeldtia “vanbredai”, Cheiridopsis dilatata and C. albirosea = I. excavata, Cheiridopsis vanzylii = I. vanzylii. There are only the two species. Hartmann, Illustrated Handbook of Succulent Plants, 2001.
Now sensibly placed in Gibbaeum (as G. nebrownii), Imitaria muirii behaves unlike all the other gibbaeums. It needs remarkably little water at any point, but I water it lightly in late summer, as otherwise it will not flower well. From early autumn (when it flowers) until late winter, I mist it frequently and water it delicately, just enough to keep it constantly plump. This treatment will nourish the flowers and fruits. In early spring it retreats into its shell and needs no actual watering; an occasional mist will suffice. In a bright position and kept in a small clay pot, imitarias will color up nicely and their subtle windowing will be more pronounced. A smaller winter-flowering variant was recently discovered by van Jaarsveld.
A small genus of two species; a few more will probably join the fold later. The plants do not sheath in summer and their leaves are only dimorphic in the juvenile stage. J. kolbei has long mahogany stems (a mitrophyllum on stilts), a pale green crystalline epidermis, and large attractive flowers, glistening white, rarely purple. J. hallii is much more compact and desirable, but it is difficult to flower and is very rare in cultivation. (Some falsely named material was distributed in the early 1980's; the true J. hallii is easily recognized by its deep green velvety leaves). Both species are winter-active and will grow in anything but prefer mabel-mix. J. kolbei needs much light to stay relatively compact; heavy pruning helps as well (the plants will resurge from short stems). It is prone to baffling depressed lesions on the epidermis. ×Jacophyllum (J. kolbei × Mitrophyllum roseum) is a very interesting plant, having the habits of the former and the superb flowers of the latter.
Note: Hartmann lists three species. The Illustrated Handbook of Succulent Plants, 2001.
The Methuselah of the family, J. lossowiana has wrist-thick stems in habitat. Potted plants don't manage such girth, but they are very easy to grow. They are not easy to grow well, as they require just the right balance of sun (for color), humidity (for turgor), and warmth. I keep them on the floor near a heater; they receive morning sun and a daily misting. The leaves should never resemble raisins. Most clones will flower in spring and tend to be self-fertile. However, some will accept pollen from Hartmanthus.
The four or more species come from the coast of Namaqualand and Namibia; they are sand-dwelling creepers and do not like pots at all. They should grow well in rockeries but, being nearly littoral, are probably not hardy. The flowers are captivating.
A small genus from the Namibian Sperrgebiet and northern Richtersveld, closely related to Dracophilus and horticulturally similar to it. Several species are uncomfortably large when mature but they can be pruned back once a year. J. kovismontana develops terrific red-tipped teeth with age, especially under hot conditions. All species have strongly scented diurnal flowers and their leaves smell like rhubarb.
Note: Quite a few taxonomic changes here. For example J. kovismontana = J. simpsonii. Hartmann, The Illustrated Handbook of Succulent Plants, 2001.
A small genus of several attractive tufted species from the high Transvaal. Khadias are very difficult in alkaline desert conditions; the greater the heat, the greater the stress, and not merely because nastily, alkaline water is applied more often! I treat khadias like tropicals, but this requires excellent ventilation and quick drainage to avoid rot. It is important to keep the fat roots as cool as possible. All species are very prone to red spider.
All khadias have wonderful flowers and are worth the hassles. I am now experimenting with K. borealis, a unique trailer which seems to be much easier than the compact khadia of horticulture, K. nationae, which requires the conditions favored by Frithia pulchra (the two are sympatric). In theory all khadias should be somewhat hardy, but you must first persuade them to thrive! K. nationae × K. carolinensis has proved to be much easier than either parent and shows neither the iron deficiency nor the yellowish heat-stress of most hybrids.
Note: K. nationae = K. acutipetala. Hartmann; The Illustrated Handbook of Succulent Plants, 2001.
A very large and taxonomically complex genus of shrubs and creepers. Almost all species have large showy flowers—indeed, if you see a nameless shrubby mesemb with flowers greater than two inches (2.5cm) in diameter, you are probably beholding a lampranthus. The plants are very easy to grow. They look best when bedded out as if they were summer annuals. In cold climates, cuttings can be taken in fall and grown on under glass. Some species will flower when small, e.g., the recently introduced L. serpens, which bears large golden honey-scented flowers. Its stems root while creeping, so its propagation should be rapid. At least a few species are summer-dormant. They are almost leafless during the hotter months, and look terribly twiggy at this time. L. scaber is the best-known of these; its marvelous flowers have a transparent delicacy.
L. margaretae is a familiar and very friendly pot plant. It grows in summer and flowers in fall, but some clones flower in spring as well. Lapidarias can maintain two to three leaf-pairs per branch simultaneously, and it is unwise to force the plant to absorb the lower leaves; you will merely starve the uppers. Best given humus-free soil and frequent light watering. I have seen a single natural hybrid with Lithops but have been unable to replicate it here.
Little-known and rarely loved in cultivation, most leipoldtias are upright shrubs with smallish flowers in winter or spring. They would look good in rockeries; in pots they tend to sprawl and their bunched flowers are an insufficient compensation. In any case they are very easy to grow and will happily sleep in summer.
Even if they all look alike, broadly speaking, not all species in Lithops behave alike. The differences involve soil preference, sensitivity to an overabundance of water and heat, flowering times, and rapidity of shrinking and sheathing. Most species will grow in any well-drained mixture, but a few, especially those in the L. comptonii complex, do best in a very firm humusless mix. These species are also the most rot-prone. All lithops will grow and thrive in deep or shallow pots; of course the available depth will affect root length, one's watering regime, and the ultimate size of the plants.
Most species receive summer rain in habitat, but there are some which are wet in winter and others which come from areas of erratic and very sparse rain. However, in cultivation all lithops without exception send forth their new heads by summer. That this is not merely a “cultural bias” is demonstrated by the behavior of seedlings. Whenever sown and however watered, seedlings eventually conform to a cycle in which they begin to expose their new heads in late winter. By summer they are ready to grow, though here we face an old semantic problem. The visible expansion of heads take place in spring and summer; but their formation occurs in winter, and even though this amounts to a usurpation of the old body's resources, it can still be termed “growth.”
L. pseudotruncatella and its variants flower in early summer, while the northern forms of L. optica (including 'Rubra') flower in mid-winter. The other species fall into the main yellow group, flowering in late summer to early fall, a few late yellows (L. olivacea and the original form of L. naureeniae), and the great white wave, which normally occurs weeks later than the main yellow one. If an adult lithops does not flower, this is not merely a disappointment for the plant: it can also impair its health, since the initiation of floral and vegetative buds is normally a twinned process. (Often the flower bud aborts at an early stage; nonetheless its surviving “twin,” the new head, will emerge normally.) It is wise to water lithops generally in summer to encourage buds of both kinds. I also water them in winter, to encourage the emergence of new bodies, but this watering is very shallow and selective, and it is superfluous or destructive where winters are dank.
Some dormant lithops make a complete sheath a la Conophytum, with only a small “air-hole” at the fissured apex. Others send forth their new bodies in a rush, and the old ones gradually wither away. This behavior is usually consistent within a species, the white-flowering ones having thicker leaves and a later ETA. If the transfer of resources from old to new goes well, the new bodies should look plump and unwrinkled; they only need a proper watering when the takeover is complete, or when they look wrinkly. If a lithops does not shed its skin by summer, it either lacks a meristem (in which case it is effectively brain-dead) or it has decided to re-use its old leaves. In that case the plant will probably survive, but it will look very weather-beaten during its prolonged sabbatical.
Lithops can be propagated from cuttings exactly as with conophytums, though rooting is slower and less certain. However, I only take cuttings of lithops which are exceptionally pretty, as they are so easily reared from seed. When pollinating lithops, you can either employ all the clones at your disposal, in an effort to reproduce the whole visible spectrum of characters, or you can mate the two most similar seedlings. This practice of refined selection, in which plants are re-selected for an intensified pattern over several generations, yields fantastically attractive specimens and it surprises me that so little of it has been done. Along the same lines, you can attempt to self a particularly good specimen and then mate its progeny. To self-pollinate a lithops, use Conophytum herreanthus pollen or simply apply a brush on several successive days.
Many hybrids within the genus are possible but most of the ones I've made are dull or ugly or both. A few have interest because they closely resemble wild species (e.g., L. gracilidelineata × L. vallis-mariae “=” L. pseudotruncatella 'Pallid form'), and a very few are really pretty (e.g., L. pseudotruncatella × L. bromfieldii). Hybrids across the “subgeneric” (i.e., the white-flowering vs. yellow-flowering) barrier are possible in the L. marmorata and L. olivacea groups, and also in L. herrei × L. optica, but the latter two probably comprise one species anyway. Hybrids with conophytums are possible but the seedlings are exceedingly weak and not promising. (However, L. steineckeana is probably a conopops, and it is indecently sturdy.) ×Dinterops is discussed under Dinteranthus.
Here are several obscure species in this small genus, some of them occurring outside (or above!) the usual succulent-rich zones. M. brevifolium is very charming, resembling a toothless faucaria, and M. albidum has large waxen greenish-white dagger leaves. The plants are most active in winter and they bear striking flowers in spring, but they like ample water year-round. Acid water helps to prevent the brown epidermal lesions to which they are prone.
The species in this weedy genus are so often ruderal (growing in disturbed areas) that I wonder how they fared before the invention of the dirt road. Certainly they are tough plants, and very difficult to identify as to species. However, some have fine flowers (salmon-red petals with a violet reverse) and at least a few are hardy, so it is well worth growing them in rockeries. I manage to keep a few in large pots by pruning them regularly.
A monotypic but polymorphic genus, recently re-examined (Hammer in Bradleya 13). Marlothistellas are very beautiful and peculiar tufted plants with fat roots, needle leaves, and, if given good light, wall-to-wall winter flowers. Easily grown, they love water and should never be allowed to flag for long. Any soil will do. They can be propagated by breaking off leaf-bearing chunks of an old caudex, but they are easy though not very rapid from seed. Plants from some populations will not accept pollen from others, so there may actually be two or three species in this genus. All bear pinkish flowers with pale stripes.
It is a pity that these “real” mesembryanthemums are so unsuited to pot culture. The large lettuce-like species are beautiful in the field but deeply uninspiring elsewhere.
Mestoklemas are loved for their large rootstocks, which are brown-barked and suitable for totemic caudex displays. (I know a gentleman who pots the ample caudexes above soil level but keeps them discreetly veiled in erotic white gauze.) The myriad leaves are small and the tiny flowers occur in coppery sprays throughout the summer. The plants sleep in winter but they are entirely unfussy and very hardy.
A tiny genus of shrublets with tangled branches which look dead all summer. There is only one “official” species with several localized forms. The best for horticulture is M. meyeri var. holgatense, which has enormous purple flowers. The Riethuis forms of var. meyeri have smaller white flowers which turn pink as they age. Plants benefit from fall pruning, which does not destroy potential flowers (the buds are formed quickly); the trimmings are easily rooted if kept moist. Meyerophytums will not flower well unless they receive ample winter light and food. M. meyeri will hybridize with Mitrophyllum roseum (very long thin leaves) and Mitrophyllum grande (stouter leaves).
Note: Meyerophytum globosum (ex-Monliaria globosa) has been added to the lone species M. meyeri. Both plants are very different to each other. The inflated, indeed bloated form of M. globosum has earned it the nickname “Michelinia” after a well known advertisement that uses a figure of a man composed of tyres. Hartmann The Illustrated Handbook of Succulent Plants, 2001.
A small genus of six published species, with more on the way. Mitrophyllums are easy but you should bear in mind that they are slow to mature (10–20 years!) and require large pots. Their habitats are semi-shaded; often the branches are exposed to sun while the trunk and the extensive roots are protected by a tangle of other shrubs or rocks. Under cultivated conditions mitrophyllums have a concentrated period of growth, from mid-fall to mid-winter, and they will flower during this period as well. The aberrant M. abbreviatum flowers in late winter, and the equally aberrant M. roseum flowers from fall until spring. These two flower when young and are the best species for horticulture. Their hybrid is a very sweet dwarf. Various Mitrophyllum species can be hybridized with:
The third of the m's in Mitrophyllinae, and the most sun-loving, monilarias come from exposed quartz patches in Namaqualand and the Knersvlakte. Very easy to grow, they are difficult to flower, which is a pity as they have the best flowers in the family. The plants split their “peas” in early fall (early watering will encourage them) and grow like grass for several weeks. During this time they require water about twice a week, and they should be placed in the brightest spot you've got, to encourage budding. Flowers appear around the solstice. The leaves collapse as soon as the warmer light of late winter strikes them. Old collapsed leaves are brittle and salty, tasting like Cantonese noodles. Seeds should be sown in hot summer. Intrageneric hybrids are easily made and florally superior; intergeneric hybrids with Mitrophyllum roseum are promising.
H.D. Ihlenfeldt transferred Monilaria globosa to Meyerophytum in [Hartmann 2001].
A monospecific genus consisting of an unusual creeper. Its stringy stems root as they go, establishing new centers of distribution. Easy to grow unless it dries out too much, M. intervallaris is best watered year round. Smoke-scented flowers appear in spring, sparingly. A hybrid with the related Neohenricia sibbettii is intermediate between its parents.
This monospecific genus has been the subject of countless virgin sacrifices since its discovery some seventy years ago. Collected seedlings and adults have been regularly deported, but amazingly enough these periodic raids have had little apparent effect on the wild population, which continues to thrive, covering the quartz like a fungus. This tells us that muirias really can grow: and the trick in cultivation is to give them a steady supply of water throughout most of the year.
The muiria cycle goes like this: in late summer the bodies leave their tattered fuzzy peels and are then most eager to grow. The plants can be lightly watered two or three times a week and misted daily. They will grow fatter and blimp-like but as long as no splitting occurs, they are safe. By winter they will need less water; ambient humidity may take care of them but the misting should continue. In early spring another round of light watering is helpful. Slowly, the bodies will change from their active greyish-green to a yellowish-green which may intensify to orange as the leaves begin to decay. By late spring the plants look bad and feel worse: softly “rotten” with sunken patches. The softening, however, allows the firm flower buds to penetrate through the tissue; the buds miss the eccentrically placed fissure altogether! Throughout this trauma, some water is still welcome, as it encourages the buds, which will wither if the roots are too dry. After flowering, the pulpy old bodies very quickly dry to a thin white sheath. Then, and only then, the plant requires no water. The actual drought may last two months, certainly not more than four. But as soon as the sheath is fully dry, you can resume watering, reducing the drought to a mere fortnight in early summer! Unless you have very hot and humid summers, nothing is gained by prolonged “rest.”
Muirias love mabel-mix. Extra grit is good too, as is a generous clay pot; the root system is extensive. Very bright light is helpful but not essential. Sow the seeds in summer in a position which receives strong light: the cotyledons should turn into beet red cones within a month and they can take almost any amount of water for the first four months. Do not transplant seedlings until the fuzzy true leaves are completely free of the bald cotyledons.
This hybrid grows along with Muiria hortenseae and in cultivation can be treated similarly. However, because of its schizoid nature it will not sheath neatly (its father, Gibbaeum album, does not sheath) and it looks messy for much of the year. The new bodies are usually born awkwardly, Caesarian-style. The various backcrosses give rise to Siamese twins, keeled globes, subtle freaks of all sorts, and phenotypically correct plants of G. album and Muiria hortenseae.
This genus was erected for N. vanheerdei, a strange shrub from a single hill east of Port Nolloth. The plants resemble astridias, but their leaves are smooth and glossy, gradually acquiring an ugly blackish soot-like coating which is apparently natural. They rest in summer and require ample water and light in winter. The flowers are spectacular, with long curling magenta petals striped pink, but they are only produced freely in bright dry winters.
Two species, mostly distinguished by floral characters, constitute this nationalistic genus. The plants like a bright situation but they dislike long droughts; in habitat they are fog-dependent. I try to emulate fog with my morning mists. Flowers usually appear in early fall, which is when I water most heavily. They are very attractive but they leave behind them an ugly legacy of slowly dying bracts. Namibias are prone to all manner of epidermal disorders which come and go without apparent cause.
A small genus of attractive tufted plants with fat roots and hardy dispositions. Some species are flooded periodically in habitat and in pots they enjoy floods as well. They like a heavy clay soil: I even dispense with pumice. Nananthus are summer growers in habitat, but under glass they function like late winter growers. A number of interesting hybrids have been made involving Aloinopsis, Titanopsis, and ×Alotanopsis.
A small genus of two or three tufted species from the Richtersveld. They are highly drought-resistant and crack badly if overwatered. The leaves are spotless and have the bland color of green bath-soap, but the cartilaginous margins are attractive. The long-lasting white flowers are bizarre and unfortunately they are difficult to pollinate, which is why the very attractive dwarf species, N. schlechteri, is so rare in cultivation. Its sinuate and minutely dentate margins are striking.
Two species, both of them tiny, grace this genus. The familiar N. sibbettii is hard to grow really well for long: it tends to die out in ragged patches, but its stems root as they travel, leaving behind a compacted mass of dead old leaves. You can conceal the die-back with bits of leaf-like grit or trim the plants once a year.
N. spiculata has larger more substantial leaves and they are retained for a longer period. Both species have odoriferous flowers, deliciously pleasant in N. sibbettii, licoricely peculiar in its sister. They are most active in spring and summer but require water at all times. Dry plants attract red spiders. Hybrids with Titanopsis are easily made and very amusing; some stomatiums also work.
Based on Bolus' misconception of Rhinephyllum pillansii N.E.Br., a species which Schwantes never saw and which thereby gained the mild notoriety it would have deserved for other reasons, being very beautiful. The genus as described belongs in Rhinephyllum, as does the species (not R. pillansii) on which it was actually based. No advice is necessary to grow mythical genera.
Note: Neorhine = Rhinephyllum. N. pillansii = Rhinephyllum muirii.
This little genus presents knotty taxonomic puzzles beyond my solving, but as regards cultivation, all real and pseudo and would-be octopomas seem to like water best when it arrives on short days. They show their displeasure by quickly wrinkling.
A small genus of thick-leaved usually toothy mat-formers. One species, O. marlothii, is ultimately long-stemmed and messy, the others stay compact. The dwarf O. herrei, with its amazingly long pedicels, is the best choice for pot-life, followed by O. nanus and the new O. angustifolius subsp. protoparcoides. A newer toothless species is still unpublished but very promising for horticulture, as is a fine new dwarf from Quachous. All species are fall-winter growers and it is wise to allow the plants to dry out between waterings. They readily hybridize with, and probably belong in, Cheiridopsis.
Note: O. herrei = O. nanus.
A genus of three very distinct species. Their needs in cultivation differ as well: O. nordenstamii is the first to waken in fall, the first to flower, and the thirstiest; O. nanum is next in the sequence; O. oviforme is last, and it must be watered cautiously because it buds and collapses almost simultaneously.
All species are sheathed by early spring and thereafter need no water until fall. They grow best in mabel-mix and need excellent light and very frequent watering to flower at all. Many growers confuse the exserted second leaf-pair of O. nanum with the leaf-pair which should emerge after flowering, and they therefore try to restrain (via drought) precisely the leaf-pair which gives rise to the flower! This misconception cannot arise with O. nordenstamii since each branch produces only a single active leaf-pair per season, and it is unlikely to arise with O. oviforme, since the second pair is wholly enveloped by the first; to starve one is to starve both. In poor light the sequences I describe are muddled or extended, but in good light they are invariable. All the species can be hybridized with each other.
Note: Hartmann does not recognise O. nordenstamii however Steven Hammer believes it is a true species.
Periodically placed in Conophytum, where I hope they will stay at last, ophthalmophyllums are horticulturally distinguished by their ease from seed and by their exceptionally soft bodies, which bruise far more easily than they rot.
One can regard the two or three (or four?) species of Orthopterum as winter-flowering faucarias with special capsules. The two genera grow together but seem not to mingle genetically, and their behaviors are quite distinct. Orthopterums are far thirstier than faucarias. The indestructible O. waltoniae is widely grown under the name F. ryneveldiae. O. coegana is rarer, both in pots and, especially, in the field, and there are one or two undescribed species as well. All orthopterums like water year-round.
Two or three species are recognized in this genus, though several similar powdery-leaved species could well be extracted from Lampranthus and lodged in Oscularia. In any case this is a rewarding genus, delightful when in almond-scented flower and attractively odd in leaf. Plants are of the easiest culture but they do best given a bright position and plenty of water; they are especially thirsty when forming buds in late winter.
Note: It now comprises 23 species many of which were erroneously placed in Lampranthus. Hartmann, The Illustrated Handbook of Succulent Plants 2001.
Two species belong here but only one, O. monticola, is familiar to me from field and pot. It is a winter grower and produces its flowers from a strange permanent perch which has fused perennial succulent “bracts.” If overwatered, the dull green leaves split along their entire length in a unique and most characteristic manner.
Sensu Bittrich this genus has been much augmented; sensu hort. (the unofficial but ubiquitous author of habit) it comprises just a few winter-growing caudiciforms. P. resurgens is a fascinating species; its lumpy broad caudex sports reddened noodle leaves covered with papillae resembling suction cups. The flowers are greenish-yellow and smell sharply of black pepper.
P. micans is similar but larger, and P. “pearsonii” has a long smoother caudex. All three should be watered at irregular intervals through the winter and kept bone-dry after the leaves die back to a brittle tuft in spring. They grow very well in mabel-mix. The leaves of some plants are prone to botrytis but this rarely spreads to other plants. I water susceptible individuals from the bottom and allow the soaking to reach only the lower half of the soil-mass. Sow in summer for flowers six months later!
Note: Hartmann does not list P. micans, while P. pearsonii = P. resurgens. The Illustrated Handbook of Succulent Plants 2001.
The sole species, P. haeckeliana, is a yellow-flowered Aptenia with stems square in section. Treat it like a water-hog and it will love you, though the feeling is unlikely to be wholly requited.
Note: Platythyra = Aptenia. Hartmann, The Illustrated Handbook of succulent Plants 2001.
The familiar split rocks have been reduced (unsplit) from the Bolusian dozens to six. Few sights in Mesembryanthema are more attractive than the pristine inner surface of a newly split “rock”; I once beheld a pair as they opened! The most rewarding species are the true P. simulans, P. bolusii, P. nelii, and a new one found by G. Marx.(???) The species are mostly summer growers, blooming in late fall. P. nelii is the exception, flowering in mid- to late winter. It does not do well unless it receives some water all winter long, as the flowers are borne by the newly produced leaf-pair, which coexists with the old for several months.
All species can take full sun, and severe drought hardly touches them, though they can burn if really dry at the wrong time. Schwantes recommended a sinecure in a warm sunny window for P. bolusii and I too have found that this species is particularly well-adapted to such a niche. Interspecific hybrids are as strong as they are ugly, while hybrids involving Tanquana (a genus segregated from Pleiospilos), especially P. magnipunctatus × T. hilmarii, are rather attractive and fully fertile. A purple-flowered P. nelii has been developed in Japan.
Note: P. magnipunctatus = P. compactus ssp. canus. The “new one” is true P. minor.
This is an unsatisfactory genus for pot cultivation, but Nature must like polymitas, having spawned so many of them. P. albiflora rarely flowers in pots; the answer is, again, a Mediterranean rockery. This species grows in winter but will continue to burgeon all year given half a chance.
Note: Hartmann lists only two species. The Illustrated Handbook of Succulent Plants, 2001.
A single aberrant species, P. orpenii, justifies this “half a genus” as Mrs Bolus called it. Better known as Aloinopsis orpenii, it is an attractive tufted mesemb with erect greyish fuzzy leaves and fine late afternoon flowers. Potted prepodesmas are active from winter though spring: indeed they are never dormant for long. In a rockery they can be treated as summer growers. They are hardy to -5°F at least. In habitat, P. orpenii grows amongst calcrete rubble; under glass it does very well in mabel-mix, especially if treated rather harshly.
A small genus with two very distinct habits: a few species produce fat-leaved mats, and one is a little bush. Though I doubt that they belong in one genus, they do have a common and unusual character: epidermal stickiness, giving them their eponymous sand-bearing quality. All are easy to grow. Their main activities occur post-summer: they produce leaves and flowers in fall and winter. Some clones of P. longifolia are very much nicer in leaf than others, having red sinuate margins, and some have violet flowers.
Distinguished from Brownanthus proper by its hard nut-fruits, which I have managed neither to crack nor to germinate intact. In any case P. nucifer is a rangy shrub of purely abstract appeal.
Note: Pseudobrownanthus = Brownanthus, Hartmann, The illustrated Handbook of Succulent Plants. 2001.
There are over a dozen species in this genus but they are hardly known in cultivation. I do cultivate one Namibian species with lizardy skin and amazing cinnamon-scented flowers. Like the other species I've attempted, it grows in winter and flowers in spring.
A mildly hallucinogenic and strongly hardy genus of mat-forming species, Rabiea is recommended for beginners. It is difficult to keep the leaves free of scars and dead leaf-tips, but the abundant flowers hide these from late winter through spring. Potted rabieas look best in a heavy soil and the same is true for plants in a rockery. They can be watered year-round. Several species names are confused and partly redundant; the Haworthian names (R. albinota for plants with thick low leaves, R. albipuncta for those with thinner ±erect leaves) seem to cover most of the forms. Some wild individuals of both species are densely covered with white spots and I am trying to stabilize this very striking character.
A taxonomically ragged genus of nocturnal and diurnal species from the Great Karoo and its southern fringes. It currently comprises two quasi-annuals (R. broomii and the rare R. pillansii); a substantial low shrublet, R. frithii; and several stomatium-like species with thick roots. Most species grow in spring and summer but they are not at all delicate and can take some water year-round. An occasional summer soaking is wise. R. broomzi is self-fertile and its fruits should be regularly plucked. Probably most species are hardy.
Note: Hartmann lists ten species. The Illustrated Handbook of Succulent Plants, 2001.
Two species, one with erect antler leaves, the other looking like a melted-down faucaria, comprise this little genus. The depressive R. rhomboideum comes from limestone belts near Port Elizabeth but it has no special cultivated sensibilities: all it wants is ample water. R. dolabriforme has various easily managed forms, some large, some dainty. Both species are active in spring and summer and flower abundantly in fall. A natural hybrid with Faucaria has been observed a few times near Graaff-Reinet.
Note: Hartmann lists five species. The Illustrated Handbook of succulent Plants, 2001.
Even with the exclusion of Antimima and Marlothistella, Ruschia is still a large and formidable genus, so broad and diverse that most horticultural generalizations are lamed. However, the species I know and grow are shrubs and creepers, and, like most leafy mesembs, they are uniformly easy. Watered amply, they retain more lower leaves while adding new ones on top; starved, they will favor the new, and abandon the old yellows. Ruschias are very active in late winter and tend to flower in spring. Most species are not showy, but there are several large-flowered species, like the superb R. marian[i]ae from Clanwilliam, R. intrusa from MacGregor, which bears huge cerise flowers in mid-winter and which belongs in another (nameless?) genus, and R. strubeniae, the carpobrotus on a stick.
Note: Hartmann lists R. marianae, while R. intrusa is now Brianhuntleya intrusa.
If you like trees in your greenhouse, you will love R. gigas; but otherwise it is better outdoors. Of its cultivation I can only guess that it would grow in winter.
“Rusch's flower” is greenish, not the least of the oddities of this monotypic genus. The whitish scimitar leaves of R. falcatus stick out at various angles. Plants produce only a few new leaves each winter, retaining the old ones for two or three years. They grow best in a very bright arid position and flower in early to late spring.
My experience with S. flaccida is very limited. The seeds need much water to germinate, and the seedlings need even more to survive; I water them daily, lest they match their name. I hope to produce more seeds eventually, for the species is critically rare, threatened as it is by agriculture and aliens.
Fewer than a dozen species comprise this curious genus; their common tendency is the “skeletonization” of old leaves, which are reduced to dry anatomized ribs and which protect new growth. At least one species is an erect shrublet (S. varians), the others form mats. All are active in late winter and spring, when they flower, and the ones I grow tend to be light sleepers in summer. Bright light and poor soil will keep them compact, otherwise they sprawl.
The species in this small genus, both of them shrubby, have firm smooth leaves, inch-long and nearly white in S. hallii, greener and smaller in S. maximilianii. Leaves are their principal appeal, for they rarely flower under glass (S. hallii produced just two flowers in six years for its discoverer and first cultivator!). Both species grow in fall and winter.
Schwantesias can be treated like lithops, to which they are related, but they do a very un-lithops-like thing: they flower sporadically throughout the year. In other words they are opportunists, and the fact that their natural habitats are caught between summer and winter rains might contribute to this. In any case they are very easily grown. Small pots and strong sun will keep them compact and white-leaved. S. borcherdsii, a recent reintroduction, is a particularly beautiful plant with rough scalloped leaves. All schwantesias (there are only a few species) can support several new leaf-pairs per year and in this sense (and others) they resemble Lapidaria.
The two “rock-born” species in this genus look their best on a rockery, naturally: they are too large for pots. The main appeal of S. gracilis lies in its ample, heavily scented yellow flowers. Both species are easy, growing year-round and flowering in spring if given enough floor space.
A very weird monospecfic genus which is essentially unknown in cultivation. I have only been able to try a hybrid (Skiatophytum × Caryotophora) and during its short and happy life this required a daily drink. I assume that proper skiatophytums, which come from wettish areas, would be equally thirsty.
A monospecific genus, widespread in the southwest Cape, and ungainly in pots. The plants grow year-round and produce their puny flowers in winter.
Sphalmanthus (fashionably a subgenus of Phyllobolus) is a diverse assemblage. For horticultural purposes I emphasize two features: the strongly deciduous tendency (many species are leafless stumps or twigs in summer), and the bizarre flowers, which have colors and scents better known from kitchens and boudoirs. Ham on an off day, wood smoke, black pepper, lemon, rose, honey, cloying narcissus, calendula: easily the widest and oddest range in the family. The dwarf S. herbertii has wonderful flowers resembling an ivory pompom mum, open day and night for weeks, and S. tenuiflorus sports many colors, from chartreuse to lilac.
All of the species I've attempted (±30) are easy to manage, but many are irredeemably ugly in pots. Usually they are active in winter, when they like ample water. Good air circulation is important, however, as they have a slight tendency to lose the lower leaves (and more rarely, the stem itself) to rot. Most species will flower within eight months from a summer sowing.
Note: Sphalmanthus = Phyllobolus. Hartmann, The illustrated Handbooh of Succulent Plants.
S. neilii, the sole species, is a large slender shrub which has no horticultural appeal beyond the raspberry scent of its fruits. It will grow whenever you let it out of its cage.
Obscure shrubs or shrublets most valuable to those who either aim for encyclopaedic completeness or have a special interest in colorless tiny flowers. Stoeberias are lousy pot plants but they might look good in vast rockeries. In any case they grow mostly in winter and spring.
Many Stomatium species or rather names are cultivated. It is very difficult to identify them all, but for present purposes they resolve to just a few. The white-flowered ones all belong to S. alboroseum. Amongst the yellows we have: the flat-leaved S. pyrodorum; the related toothless giant, S. agninum; the beautiful S. suaveolens, forms of which have purple leaves and orange-yellow petals; the basic Haworthian S. ermininum; and various red-toothed or tiny-leaved glaucous species.
S. alboroseum is a Bushmanland species which grows in fall, flowers in winter, and then rests. The yellow species, largely from the Great Karoo, tend to grow in spring and summer after they flower in late winter — but no stomatium is particularly strict and all are ambrosial from the narrowly focussed viewpoint of mealy bugs. Stomatiums grow best in hard soil; given trapped heat they look wonderfully burnished (they grow very well in cactus ovens), but best of all, many or most are hardy and they look fine in a cold greenhouse, frame, or outdoor rockery. Wherever you place them, they should be within sniffing distance as their night perfumes are delicious.
All species are quick and easy from seed. They will hybridize with Titanopsis (day meets night), Neohenricia, and to a limited extent with each other (S. agninum × S. pyrodorum, but the former species will sometimes self).
Note: S. pyrodorum = S. mustelinum. Hartmann, The illustrated Handbook of Succulent Plants, 2001.
This Namibian genus is known to me from dried material and from three tiny seedlings. From those I judge that S. juttae, the only species, is evidently very thirsty. In habitat the plants are reddish.
Note: “The tube-shaped connate leaves probably aid the collection of dew droplets, which according to Bittrich (1987), can effectively be absorbed by the leaves.” Hartmann, The Illustrated Handbook of Succulent Plants. 2001.
The three species in this genus resemble the three bears. The baby, T. hilmarii, is reduced to a single tiny head while the gross papa, T. prismatica, forms mats a foot across. All grow a la lithops, with little visible activity long after their fall flowering, and all are easy to cultivate. They need very strong light to bring out the bronze epidermal colors. T. hilmarii should be given a clay pot in humid climates.
Horticulturally the Titanopsis species fall in two camps: the easterners, T. calcarea and the probably synonymous T. fulleri, which grow in summer and flower in fall, and the westerners, T. schwantesii (including, sensu lato, T. luederitzii and T. “primosii” L.Bolus ms.) and T. hugo-schlechteri, which flower in winter or spring and which tend to grow in winter. Some forms of the western species intergrade and these plants are puzzling but highly attractive (imagine a glaucous T. schwantesii). T. hugo-schlechteri, especially at the seedling stage, is rot-prone, and good air movement is vital. Water seedlings very cautiously until they have passed the critical three-pair stage. Otherwise, when given mabel-mix and strong light, these plants are easy to grow and look amazingly like limestone rubble or shards of Pompeian polychrome.
Note: T. fulleri = T. calcarea while T. luederitzii and T. “primosii” = T. schwantesii.
A mid-sized genus full of complex characters and character. I have no idea what to call most of them but fortunately Ingeborg Niesler (Hamburg) is revising the genus. Here I will mention only a few tendencies in the genus: caudiciform bases, luxuriant flowers, and of course the famous leaf-topping diadems. All species known to me are of the easiest cultivation. They tend to grow and flower in spring, when their water needs are highest. I list a few choice species: T. fergusoniae (= T. strumosum?), which has a rounded caudex and beautiful red-striped petals; T densum, which is covered in gaudy bloom every spring; and T. decorum, which tends toward unwelcome volume but which produces orange petals with red backs.
Note: Hartmann treats both T. fergusoniae and T. strumosum as valid species. Illustrated Handbook of Succulent Plants, 2001.
A tiny genus of two or three species (unlike Hartmann, I recognize both V. roodiae and V. divergens) with considerable appeal in cultivation. However, they only reveal their beauty in good light.
V. primosii is a dwarf with lithops-like bodies and windows, and—here is the obvious distinction—toothy keels and margins. V. roodiae is a larger, non-windowed version of V. primosii, and V. divergens has even larger purplish bodies with sharp serrate keels. All species are sheathed in summer and the leaves gradually emerge in fall, with full development in late winter. In early spring they bear one to three flowers per body and then begin their annual retreat. They grow best in mabel-mix and I water them, especially V. primosii, very lightly and very often. The two Hartmann species can be hybridized with each other, thus giving us a windowed V. roodiae, and that species, unadulterated, can be hybridized with Titanopsis schwantesii (T. “primosii”).
Not to be confused with the van Zyl of the famous Dinteranthus species, and not likely to attract much attention in horticulture though the genus has a curious charm for me. The only recognized species, V. annulata, has several forms, all with narrow leaves at the end of erect wiry branches, all going into a sheathed summer dormancy a la the related Cheiridopsis. The flowers appear in mid- to late winter and have odd shades of greyish-white and smoky rose.
A tiny genus with one tiny species, causing big problems in cultivation. V. ater alters or extends its leaf sequences in a pot and generally fails to flower, but this past winter has been so sunny that the plants have developed properly and as of this writing (February 1995) they are in full bud. Like many alpines, they require excellent drainage and good air-movement. They go deeply dormant in summer. Since I observed them in snow, I assume the plants have a certain degree of hardiness.
Not to be confused with Haworthia woolleyi von Poellnitz, though it is also rare in horticulture. (I do not know why Major Wooley's surname appears with and without a doubled “L”!)
W. farinosa is a shrub with white-powdered leaves; the surface resembles that of flour-dusted potato bread. It is a tolerant species, staying white even in partial shade, but it likes heat and strong sun as long as it is deeply watered every two weeks or so. The large but non-showy white flowers appear in winter, tending to blend in with the leaves.
Another lost genus and, I fear, cause. Z. suppositum was or is a horribly named shrublet from the Phisantefontein area, and to judge from the material at Bolus and from the single capsule at Hamburg, was quite robust. The photograph in Jacobsen's 1960 Handbook appears to be authentic, while the painting in Herre is a latter-day concoction, but most or all of the “zeuks” in cultivation are members of Octopoma sensu confuso.
Note: Hartmann includes two species Z. (nee Octopoma) calycinum and Z. supossitum. Illustrated Handbook of Succulent Plants, 2001.