A Layman's Guide to
Mimicry Mesembryanthemums

by Ken Hancock
(drawings by the author)

  1. WHAT ARE THEY?
  2. HABITAT AND CULTIVATION
  3. LITHOPS
  4. DINTERANTHUS, LAPIDARIA AND ARGYRODERMA
  5. CONOPHYTUM & OPHTHALMOPHYLLUMS
  6. FENESTRARIA AND FRITHIA
  7. PLEIOSPILOS AND GIBBAEUM
  8. TITANOPSIS AND CHEIRIDOPSIS
  9. REFERENCES

WHAT ARE THEY?

Mimicry Mesembryanthemums is a rather loose term used to describe a group of South African succulent plants of a number of different genera (a botanical term for a group of plants based on them having similar types of flowers and other basic characteristics) in the family Aizoaceae. They include Lithops, Conophytums, Fenestraria and about 14 other similar genera.

The term Mimicry Mesembryanthemums, or Mimicry Mesembs for anyone like me who finds that a bit of a mouthful, is used because in general these plants tend to resemble, both in shape and colour, the stones and pebbles of the rocky deserts of their natural homes. The only thing wrong with the term is that it tends to make you imagine that in some strange way the plants look around and think something like "My, I'm living in a place full of round grey stones, I'll make like I'm a round grey stone and maybe I won't get eaten by those darn Springbok." Of course being only plants this just doesn't happen. As a result of natural selection (the Springbok maybe did eat those that were way out) and evolution over millions of years, these plants have developed forms that allow them to live in the unbelievably harsh conditions of their natural environment.

To give an idea of what I mean some Mimicry Mesembs have been known to survive THREE YEARS without rain, living on dew only, in areas where the harsh sand-storms can strip paint from a car right down to the bright metal in a few hours. The summer temperatures in these deserts reach 45 C in the shade, and the browsing animals (yes they live even there) strip every sign of twig or plant.

Perhaps the best known genus of the Mimicry Mesembs are the Lithops. The name Lithops is made up from Greek words meaning like a stone and they were first discovered by naturalist Williams Burchell in the Karoo desert in South Africa in September 1811. In his book Travels in the Interior of Southern Africa he writes "On picking up from the stony ground what was supposed a curiously shaped pebble, it proved to be a plant, and an additional new species of the numerous tribe of Mesembryanthemum, but in colour and appearance bore the closest resemblance to the stones between which it was growing."

He named it M. turbiniforme, which was changed later to Lithops turbiniforma. It is now found in many collections and is of a reddish-fawn colour mottled with lines of a darker colour. The yellow flowers are bigger than the plants.


Figure One: Some Mimicry Mesembs

Another Mimicry Mesemb genus popular with collectors are the Conophytums. There are some 400 different species, all of them with quite small individual bodies. As with all the Mimicry Mesembs they have specific growing and resting periods, varying somewhat with the different species and corresponding to the wet and dry seasons of their natural habitat. In general Conophytums are winter growers in Canada and, as in common with all Mimicry Mesembs, they need a lot of sun and light to bloom, it is unusual to see the flowers in this country unless grown under flourescent lights in the winter. The flowers are very dainty and beautiful, and often twice the diameter of the plant. During the resting period young plant bodies are formed within the old, which dries to a papery insulating skin which protects the new plants from the fierce heat of the sun.

HABITAT AND CULTIVATION

The Mimicry Mesembryanthemums are exclusively South African plants. However South Africa, like Canada is a pretty large place, and the climate varies quite a lot from area to area. To give us a clue as to the sort of cultivation we should use it is a good idea to find out in which particular part of South Africa our plant grows in the wild and base our culture on the natural conditions and soil found there. By South Africa I mean the Southern part of continental Africa, which is generally but not exclusively the Republic of South Africa.

Fortunately however, mesembs, like people, are very adaptable so we don't have to provide a miniature South Africa in all details for our plants to survive. In fact if you stick to four rules of thumb you can very successfully grow nearly all Mimicry Mesembs, These are:

  • Always given absolute maximum light and sun. The only exception to this is seedlings in their first year.
  • Water only in the growing season and then soak about once a week. When in doubt DON'T WATER. Where the resting season is in the winter and central heating gives very dry air in the home, give a light top spray once a week to simulate the desert dew and prevent excessive dehydration.
  • Use a sandy open soil with a fair amount of lime (pH factor in the order of 5 to 10). Good drainage is critical.
  • Never let the temperatures go below freezing, preferably not below 5 C. Strictly speaking this applies to most but not all species, but unless you know the hardiness of a given species (and these are not well established) it is wise to keep to this rule.

Remember that most Mimicry Mesembs that die in collections die from over-care of the wrong sort rather than neglect, so if you get a new plant that you are not sure of, put it in a sunny window and forget it until you can find out more about it. Most of these plants use the shrivelled outer skin of their old body to protect them during the hot resting season, using the moisture from it to grow a new body inside. So don't throw your plant away if it looks all withered, and above all, don't be tempted to water it excessively as the resting season is when the plants are most prone to rot. I have had collected plants that have arrived from South Africa, shrivelled and dead looking with only a tiny broken fraction of its original top root, and which remained that way for up to nine months before showing signs of new growth, and then with judicious watering, plumped out into beautiful healthy plants.

Getting back to the habitat of our plants perhaps the most important thing to know is the rainy season and thence the growing period of our plants. Those that come from the Karroo, such as Pleiospilos, some Lithops and some Conophytums, grow in the summer when this area gets its sparse rainfall, whilst those that grow in for example, the Southern Cape Province where it rains in the winter, grow in the winter. Examples of winter growers are Opthalmophyllums, some Gibbaeum and many Conophytums, particularly those with rounded bodies rather than those with ears.

These growing periods are triggered by the seasonal variations of daylight, rather than the calendar month, so if plants grow in the South African winter, say May to September, they will grow in our winter, say November to March.

Propagation of Mimicry Mesembs is in general from seed, although in some cases where multiple plant bodies form these can be separated and often quickly form their own roots in damp sandy compost. More details of growing from seed are given later regarding the individual genera, however a usually common characteristic of the seed is its very small size.

When growing Mimicry Mesembs their appearance is greatly enhanced if they can be grown in the appropriate setting. If the pots are set in gravel, or holes in a staging, up to their rims, and then the whole area strewn with sand and stones of the right colour, the mimicry aspect of the plants will be immediately obvious. In fact some visitors will have to be persuaded that you really are growing plants and do not just have a container full of stones!!

LITHOPS

Lithops are most people's introduction to the Mimicry Mesembs and are deservedly very popular. They really live up to their common name of Living Stones or Stone Face, are reasonably easy to grow and flower, are quite small, the largest having bodies about 4 cm diameter, and 3 cm high, (this is especially useful in the winter when they have to be brought indoors) and are fairly easy to obtain.

Some growers do not feed their Lithops at all, arguing that there are enough nutrients in the potting mix. However, it is often useful to feed a few times in the summer with a bloom-inducing (high phosphorous) plant food at 1/3 strength. This encourages blooming in the fall. Too much feeding will result in bloated plants.

Lithops don't mind warm temperatures in the Summer, but they can burn in direct searing sun.

One of the big problems facing collectors of Mimicry Mesembs is that of naming them. This is particularly difficult with Lithops as the differences between species are mainly in colouring, the differences in form being generally quite small. In addition controversies are still raging between botanists as to the correct names for certain types, and whether or not some species should be combined with others and so on.

Those described below are a personal selection from my own collection or which I have grown in the past, which are fairly easy to come by and are reasonably distinct from other species.

L. bella - (Beautiful Lithops). Has a pale stone-coloured body with dark greenish-brown markings in depressions in the rounded yellow-ochre coloured top. The older plants form clumps of ten or more plant bodies. Each body is around 3/4 inch in diameter and up to 1 inch diameter. The flowers are snow white.

L. divergens. Grey-green body with large grey windows on the rounded top making the plants look as though they are filled with liquid. The colours tend to fade a little by the end of summer. The growing cleft is fairly wide and the plant bodies, which seldom form clumps, are about 2.5 cm in diameter and 4 cm high. The flowers are large and yellow, completely covering the plant.

L. fulleri. This is one of my personal favourites, it is around 2.5 cm in diameter by 2.5 cm high. The growing fissure extends right across the rounded top but is quite shallow, around 3 mm deep. The body is pinkish with a flat lavender top with milk chocolate brown markngs on it. The flowers are a pure white.

L. lesliei. This is one of the largest Lithops, up to 6.5 cm in diameter and 5 cm high, forming fairly large clumps quite readily. The sides of the bodies are a light velvet brown with the flat top a light reddish brown with dark brown mottling. The growing fissure tends to be quite small and closed at the edges. The large (up to 8 cm in diameter) flowers are dandelion yellow.

L. localis var peersii. This plant was previously called L. peersii but the botanists have now lumped together with L. localis as a variation. This is a beautiful dove grey plant with a pinkish grey slightly rounded top having a fine dotting of brown. It clumps freely and is of a medium size, around 2 cm diameter with a fairly wide shallow growing fissure. The flowers are bright yellow with a thin white eye.


Figure Two: Some Popular Lithops

I will go on to the cultivation of Lithops and for this I couldn't do better than to quote from Marjorie Shields' excellent article from the Nov./Dec. 1968 issue of the African Succulent Plant Society Bulletin.

"Contrary to the prevailing idea, Lithops are not difficult to grow when once the growing cycle is understood, and this is the cycle. Cease watering as soon as the flowers fade and do not water again until the old bodies are reduced to a papery skin and new bodies have emerged to take their place. Then recommence watering, increasing the amount as flower buds appear, ceasing again as the blossoms fade and the seed pods form. It is as simple as that.

Do not think for a moment that the plants are resting or are dormant during the dry winter and spring period when no water is given. Far from it! They are working hard producing a new plant and they prefer to do this unaided, without any help or interference from us. While we were busy watering during summer and autumn, the plants were also busy, storing up that water into their swelling bodies and turning it into plant food ready for the new plant to feed on, and which begins to develop as soon as the flowers fade. From now on this developing plant relies entirely on the nourishment provided for it in the body of the parent plant, which has now stopped growing. It is useless watering it for as the roots have ceased to function more harm than good may be done, as the damp soil could cause them to rot.

The roots now look more like pieces of stiff, frayed string than roots and appear completely dried up and dead. This I discovered when, with much trepidation, my plants were transferred from tins to the open bed in the spring of the year, so even though you see the once beautiful bodies shrivelling, don't be tempted to water. The plant is not drying, it is just a natural process for the old bodies to shrink and shrivel as all the nourishing substances are drawn from them by the young developing plant. But once the goodness has gone from the old leaves, the roots again come to life, for the new plant must be fed. Thick white roots now appear at the tips of the dead-looking, frayed, stringy ones. This to, I say, when transplanting them, as one Lithops was further advanced than the rest.

When the old bodies are reduced to a papery skin, this splits and the plant emerges - a real living gem stone, its pristine beauty neither marred by weather nor faded by the hot sun. The plants may now be watered regularly. As the outer covering begins to disappear it is not wise to help it along by peeling it off yourself, for the plant underneath could be damaged in the process and the tender skin suffer sunburn, so leave it to nature. By now it will be early summer and this is the time to repot if necessary, but as the plant uses the soil for only three or four months in the year a Lithops may remain in the same pot for several years and come to no harm, only if it is a clustering type, repotting into a larger container may be necessary.

Cuttings may also be taken at this time of the year - early summer - by removing a body very carefully, cutting it off below the body with a pair of fine pointed scissors, take care not to cut or damage the plant in any way. Set the cutting in sandy soil and after a week or two slightly dampen the soil when roots will soon appear and it will also flower later on in the same season, for this is a mature plant and not a seedling.

A very sandy soil is necessary - half coarse sand and fine gravel to equal quantities of loam and leaf mould suits them well. When planting see that the roots go down quite straight - this is important.

After planting cover the whole surface with fine gravel, thick enough to keep the plant bodies away from the soil.

Seedlings are treated in the same way as adult plants only, as they shed their skins more frequently, water only when they break though them and cease as soon as the bodies show signs of shrivelling. This happens several times during the year, more frequently when very young and as they grow, not so often. So watch the plants, they will tell you when and when not to water, but keep them growing."

DINTERANTHUS, LAPIDARIA AND ARGYRODERMA

These three genera are quite similar to Lithops and in the case of Dinteranthus and Lapidaria can be considered as slightly more advanced forms of Lithops. In fact until fairly recently Dinteranthus were lumped together with Lithops.

Perhaps a word of warning is in order before we go too far. Although both Dinteranthus and Lapidaria are very beautiful genera and a real joy to see in any collection, they are by no means beginners plants, having a very great tendency to up and die if the conditions are not exactly right and, sometimes it seems, even if they are!

Argyroderma are somewhat more tolerant. For example with regard to over-watering are very greedy drinkers and split within a day or so if given too much water, thus letting us know of our error before rot sets in and the plant dies. Although the split of course disfigures the plant, this is not a major disaster as the following season, when the old body has shrivelled, the new one appears clean and unblemished.

All three genera are summer growers and, perhaps even more than other Mimicry Mesembs, need full bright sunlight throughout the year. I normally water by plunging the pots in lukewarm water to the rims and removing them as soon as the surface of the soil has dampened, then allowing them to drain well. This is done about once every two weeks during the growing season depending on the humidity of the air, but not at all during the resting period. When buds appear a little water is given but not too much.


Figure Three: Dinteranthus, Lapidaria and Argyroderma

Every grower has their own pet soil mixture for these genera and I give mine for what it is worth, but as long as the general principal of an open, sandy, somewhat alkaline soil is adhered to, I feel that the precise proportions are not overly critical.

4 parts sifted loam
4 parts sandy gravel
2 parts sifted leaf mold
˝ part crushed plaster or other form of lime
˝ part wood ash or crushed charcoal

Now for the individual genera, let us start with Dinteranthus. Named after a renowned botanist, Kurt Dinter, there seem to be around seven species to this genera as follows: D. inexpectatus, D. microspermus, D. pole-evansii, D. puberulus, D. punctatus, D. vanzijlii, and D. willmotianus.

There is little in the literature on this genus and there may well be other species, or some of the above may be synonyms. The genus seems to be in general short-lived, most plants living only four or five years, but D. vanzijlii seems to be an exception to this. Dinteranthus seeds are very small, virtually dust like.

The three species that I have grown, D. pole-evansii, D. puberulus and D. wilmottianus are all a very beautiful dove grey colour, the surface having an almost velvet finish. D. puberulus and D. willmottianus have darker grey dots, the former all over, the latter with few if any in the growing slit. D. pole-evansii whilst solid dove grey, has a slightly waffled surface and is flat, only about 0.5 cm and oval about 5 cm by 4 cm with a narrow growing slit. The other two have been sketched approximately full size, the D. puberulus is shown with the new body just emerging. The old body does not shrivel so quickly as in Lithops and sometimes persists for the second season.

The genus Lapidaria has only one species, L. margaretae. In general form this is like a Lithops or Dinteranthus with a very wide growing slit. However the old bodies persist for several years without shrivelling, the two halves growing wider apart as each new season's body appears. The colour is a delicate pinky grey. Cultivation and soil are the same as for Dinteranthus. The sketch is approximately full size.

Argyroderma were first described by William Aiton of Kew Gardens in the mid-eighteenth century. In general these plants look like domed blue-green Lithops. There are however exceptions and A. brevides and A. braunsii are both finger like. This is another genus where the names are in a somewhat confused state, and whilst fifty different species are listed, many of these are likely to be synonyms or varieties. As with the other two genus described, Argyroderma only flower and grow to their striking blue-green shade if grown in full sunlight, otherwise they take on a washed out light green colour.

Although a little more robust than Dinteranthus, cultivation and soil are similar, however a little more water can be given.

CONOPHYTUM & OPHTHALMOPHYLLUMS

The two genera mainly grow during the winter in the Northern Hemisphere and rest during the summer, and as in common with all mesembs need a lot of bright sunlight to bloom so flowers are rather difficult to achieve unless artificial light is used or we have a really sunny fall.

As you may have noticed, throughout this paper I have been stressing this characteristic of the Mimicry Mesembs, both summer and winter growing, of needing a lot of sunlight. It holds for all mesembs and really cannot be over emphasized if you want to grow good plants. In fact the very name refers to this need as Mesembryanthemum is Greek for mid-day flower, the flowers only opening under the bright mid-day sun, and closing again before dusk.

Of the two, Conophytums are the easiest to grow and have the advantage of being fairly readily obtained, and as there are some four hundred species there is plenty of choice. Conophytums are among the smallest of the mesembs, just about all of them can be grown in 6 cm pots, at least for a good few years until they have a large number of plant bodies. Like most Mimicry Mesembs they can multiply by growing two bodies within one old one during the resting period, during which time the old body shrivels to a parchment like skin covering the growth, which bursts through in the growing season when water is given. A point to note is that most Conophytums have small hair like root systems so are quite prone to being knocked right out of their pots by careless handling.



Conophytum pellueidum ssp peupreatum
Photos by: Hilda Maxwell
Specimen by: Ken Hancock
November 9, 2002

The various species show considerable variations in shape and colour, going from flat pancake shapes through small balls to the eared or heart shaped types. The colours vary from a plain pale chalky green to dark green with bright red dots or mottling. The flowers, whilst usually small, have the attractive appearance of tiny stars, white or yellow.

The three I have chosen out of my own collection to describe in detail are representative of these widely varying forms.

Conophytum obcordellum. This is a small pancake shaped plant, around 1 cm in diameter with a small growing cleft that doesn't reach right across the body. The sides are pink to a deep dark red and the top is a medium green with dark green dots that are slightly raised, which sometimes join up to make lines and which turn a beautiful bright red during the resting period. The flowers are a rich creamy colour with a pale yellow centre and the thin petals form an almost star-like structure. This species was originally discovered in the Van Rhynsdorp district of South Africa.

Conophytum percrassum. This plant has upside down pear-shaped bodies, usually more than half covered with previous years' light brown tissue like skin. The colour is a light shiny bluish-green with very small, hardly noticeable dark green dots. The growing cleft is small with a length of only about one-third of the diameter of the body and shaped just like a pair of lips. The diameter of the body varies greatly and can be between 0.75 cm and 2 cm. The flowers are largish, up to 2.5 cm in diameter with shining yellow petals and a high wine-coloured centre. This plant originally came from Little Namaqualand in Africa.

Conophytum bilobum. This is one of the heart-shaped or eared species with, for Conophytums, a large body up to 4 cm high and an 2.5 cm in diameter with the ears up to 1.5 cm long. It is a plain pale bluish-green in colour, sometimes with a tinge of red. The flowers are up to 2.5 cm in diameter and are a shining yellow with an orange centre. This plant also comes from Little Namaqualand and whilst it is a fairly slow grower, is not difficult and flowers fairly easily.


Figure Four: Conophytums and Ophthalmophyllum

Let us now consider Ophthalmophyllums. Looking somewhat like fairly tall thin Conophytums with small ears, but having clear windows on top of the ears, through which the light gets to the chlorophyll inside the body for the plant to grow. The name is Greek for eyed leaf. There are about five species that all look fairly similar differing only slightly in shape and shade so I will only describe one in detail. Cultivation is similar to that for the Conophytum, lots of light, water about every ten days in the growing season and little or no water during the rest period.

Ophthalmophyllum frierichiae. This, the first of this genus to be discovered, was found in Warnbad, South West Africa by Fran Dinter. It usually only grows the one cylindrical reddish green plant body, up to 4 cm high and up to 1.5 cm in diameter. In its natural state only the top of the ears with the windows show above the ground. The flowers which bloom around September - October time are white with yellowish centres.

FENESTRARIA AND FRITHIA

These two genera, which are superficially very similar, are club leaved window plants. Both are quite fascinating to grow and are comparatively easy providing certain precautions are taken.

First the Fenestraria, the name meaning a number of windows in Latin. These stemless plants consist of a number (up to twenty or so) of club shaped opposite reddish green leaves of almost circular cross-section. The leaves, which grow almost vertical, have dome shaped tips with dark green windows in them. The leaves in their natural habitat are buried in the ground except for these windowed tops which often look like the eyes of sand lizards that also bury themselves in the sand. The plants pull themselves down by their strong contractile roots. All the photosynthesis, by which all plants grow, is carried out through these small windows (about 5 mm in diameter) so it is very important to give both Fenestraria and Frithia maximum light.

One of the main things to remember with Fenestraria is that it hates to be moved so it is best to grow these plants from seed. All of those I have been given or bought have died. Growing from seed is fairly simple if the seeds are kept around 25 C and fairly moist. They should be pricked out, singly into 8 cm pots as soon as they can be handled keeping these pots as their permanent homes. The soil should be similar to that given for Dinteranthus. Water Fenestraria with care, about once every two weeks in the summer and once a month to six weeks in the winter. Winter at a fairly high temperature, say around 16 C. Under these conditions the plants will grow quickly and well, up to fifteen leaves in the first year. There are only two species in the genus, F. rhopalophylla and F. aurantica.

F. rhopalophylla. This species was discovered by Dr. L Schultze near Princes Bay in South West Africa. They gather water from the mist that forms in these coastal regions with fine auxiliary roots that spread widely very close to the surface.

The leaves are up to 2.5 cm long and around 7mm across the rounded turbicles at the top tapering to around 5 mm at the base. The flowers, which bloom in August are a shining white. In the older plants the roots branch forming a short underground stem so that the plant forms clumps.

F. aurantica. This species, whilst a slightly greyer green than F. rhopalophylla is virtually indistinguishable from it when not in flower, even when the two species are grown along side each other. However, its' flower is larger and a beautiful orange. Another difference is its tendency to clump far more than the other species.

It was discovered to the South of the Orange River in South Africa by Mr. Pillans.


Figure Five: Fenestraria and Frithia

Frithia at first sight looks like a Fenestraria, however botanically it is quite different. The leaves are rough not smooth as in Fenestraria, and are alternate not opposite. As the plant is stem-less, this means the leaves appear singly. The flower is also quite different.

F. pulchra. The only species in this genus has leaves around 1.25 cm to 2 cm long, a little greyer green than either of the Fenestraria species with a wide windowed tip which gives the plant its common name of Fairy Elephant's Feet. The flower is large, often up to 5 cm in diameter and set on a very short stalk so that it virtually hides the plant. It is carmine for about 1 cm at the edges with yellow inside.

It is raised easily from seed and is cultivated in the same way as Fenestraria.

PLEIOSPILOS AND GIBBAEUM

The genus Pleiospilos when grown properly is one of the most stone-like of the Mimicry Mesembs, resembling not rounded pebbles like the Lithops but angular rough pitted chunks of rock. The name is Greek and means full of dots, referring to the usually dotted surface of the plants.

All species come from the Karroo desert in Cape Province, Africa and are almost stemless plants with one to three pairs of usually angular thick leaves joined at the base. In some species there is a chin-like ledge on the underside of the leaf.

This genus is comparatively easy to grow and will reward good culture by producing its large flowers, usually yellow, regularly every fall. They are summer growers and like a fair amount of water during the growing season. Like many other Mimicry Mesembs during the resting period they will absorb nourishment from the oldest pair of leaves to grow a new pair. In general Pleiospilos are fairly tolerant of such abuse as being watered during the resting period or being deprived of sufficient light insomuch that they usually survive. However they will not develop their full beauty as mimicry plants growing strings of fleshy green leaves quite unlike the natural rugged growth of a few pairs of leaves of rock like texture.

There are around thirty different species in the genus, many very similar to each other but the three detailed below are representative of the main types.

P. bolusii

This popular plant is a very good example of mimicry, the single pair of leaves resembling two angular chips of granite, each around 6.5 cm long and almost as broad. The keeled underside of the leaf is carried over to the end of the leaf giving the characteristic chin-like appearance of this species. Some plants which are sold as P. bolusii but which do not have these leaf tip chins are usually a hybrid between P. bolusii and other species.

P. hilmari

This species looks very like an Argyroderma at first glance, having a single pair of reddish green leaves with dark spots, which are joined at the base and look like a round pebble split in two. The flowers which have very short stalks are about 2 cm in diameter and are a typical golden-yellow.

P. simulans

This plant normally has three pairs of leaves, one pair fully mature, one pair shrivelling and one pair growing. The leaves look like angular splinters of rock, flat or concave on top with a keeled lower surface but no chin. They are up to 8 cm long, an inch and a half wide and around an inch deep. The leaves are mid-greenish with yellow, dark green and red flecks and dots. The flowers which are often borne in clusters of two or three and are sweetly scented yellow, and are often up to 10 cm in diameter, almost covering the plant.


Figure Six: Pleiospilos and Gibbaeum

The Gibbaeums are a widely varying genus, the different groups of species not only look unalike but have different growing and resting periods.

The name is derived from the Latin, ‘gibba' meaning ‘hump' and refers to the shape of the leaves. The leaf pairs are of unequal length and one of them is more of less humped.

There is considerable variation in leaf shape in this genus. Some species even resemble Conophytum or Argyroderma while others are more like Glottiphyllum. Most species of Gibbaeum grow in winter but many species grow when they feel like it. They will grow when water and sunshine are given and temperatures are moderate.

The Gibbaeums which choose to grow in summer stop growing when heat is high. The summer growing species are rested (stop watering) from autumn until spring. For winter growers, watering is stopped from about June to November.

Some like G. album are spherical with the growing cleft hardly visible, others are finger shaped as in G. pubescens and yet others have flat triangular leaves. An interesting point of most of these plants is that the leaves of a pair are of different sizes and the divisions between them oblique.

However, nearly all the species of this varying genus, come from one comparatively small part of Africa, the Little Karroo, in the west of Cape Province. They should be watered about once a week during the growing period and kept quite dry during the resting period.

As well as being grown from seeds most Gibbaeums can be propagated by cuttings planted in damp sand or vermiculite.

G. heathii

This species form more or less flattened spherical bodies with an irregular split which is off-center. They form widely spaced clumps joined together by a common root. The bodies which are grey-green and smooth are up to 5 cm diameter. The growing period of this species is in the spring from March to about June, the creamy-white flowers with the petals tips tinged with pink appear early in the growing season.

G. velutinum

This plant which although hardly a Mimicry Mesembs is included here to show the variation of this genus. It forms loose clumps on short woody stems, there being two or three pairs of triangular cross sectioned, and different shaped leaves of unequal lengths to each clump. Each leaf pair looks as if it was formed from a single leaf slashed irregularly down one side. The growing period of this plant is in the winter and, compared with some other Mimicry Mesembs, has a comparatively long growing period of September through to May, flowering in the fall.

G. album

This plant which is quite rare also forms open clumps. The spherical leaf pairs are around 2 cm in diameter with a hardly noticeable central growing cleft. The growing period is also in the winter from November until May flowering from December to February. The white flowers are around an inch across.

TITANOPSIS AND CHEIRIDOPSIS

In this final section, we will discuss one of the few Mimicry Mesembs that has a rosette form, the Titanopsis; and a genus that in some species varies quite considerably during its growing period, Cheiridopsis.

The genus Titanopsis was first discovered by Professor Marloth in Cape Province, South Africa, around 1907. He leaned against what he thought was a sterile limestone cliff and found that his hand had crushed a small plant. Writing about it later he gave his opinion that it was the most perfect example of mimicry among the Mesembryanthemaceae. The generic name reflects this comment, coming from the Greek words titanos (chalk) and opsis (appearance). This refers in particular to the first species found, T. calcarea, although all species are fairly similar.

The plants are small, up to about 6.5 cm in diameter, and either stemless or with very short stems. Six to ten leaves cluster on each shoot, tightly packed into a rosette. The leaves are narrow at the base, broadening to the roughly triangular tips that are usually quite thick. The background colour is a grey-green but the contorted triangular tips are covered with white, yellow or red warts and when examined under a magnifying glass show quite beautiful patterns and colours.

When in the wild, or when grown under the correct conditions in collections, the leaves forming the rosettes grow close together and are somewhat twisted and distorted. Contractible roots pull the plant into the ground during high summer so that only the warty tips show, giving the plant the appearance of weathered chips of limestone.

Titanopsis should be grown in full sunlight, in an open gritty soil with some limestone chips or other form of lime added. They are summer growers and should be watered judiciously from April to October, bearing in mind the arid conditions of their habitat. There are six species that are currently considered to form this genus, as follows:

T. calcarea. The rosettes form clumps. The warted tips of the leaves are whitish and reddish brown. The flowers are a golden yellow and quite small, some 2 cm in diameter.

T. fulleri. Greyish brown warts, flowers dark yellow.

T. hugo-schlecteri. Occurs in two forms, on with reddish, yellow, bluish, green leaf tips, and the other with bluish-green tips. Flowers are a brilliant orange.

T. luederitzii. Fairly narrow leaves with ochre coloured warts and yellow flowers.

T. primosii. Flesh coloured warts and canary yellow flowers.

T. schwantesii, with T. calcarea, my own favourite. The reddish yellow warts are larges and sometimes domed. The flowers are a pale yellow.

A number of other plants, originally placed with Titanopsis, have been transferred to a nominally similar genus, the Aloinopsis, leaving just the six species mentioned above.


Figure Seven: Titanopsis and Cheiridopsis

The genus Cheiridopsis contains a hundred or so different species of quite widely varying form and habit of growth. In addition some are winter growers, and some rest in the winter. Not all of them can be said to be Mimicry Plants. In the face of diversification I will select samples of the most interesting and available species and describe them.

The name again comes from two Greek words, cheiris (sleeve) and opsis (appearance) and relates to the fact that the first species discovered have sleeve like leaf sheaths, that, when dead and dried to a brown wrinkled skin during the resting period, remain intact, protecting the new succulent leaf within from the scorching sun.

C. cigarettifera which was apparently the first species to be discovered has quite short slim leaf pairs around 2.5 cm long. The dried sheath completely covers the resting leaf pair giving it the appearance of a cigarette stub. The plant forms clumps and grows from July to March.

C. peculiaris has large leaves which spread out and lie flat. Above these is a pair of completely united leaves through which the next pair grows, the dried sleeve protecting the new growth. Growing period September to May, flowering from April to May. This species is comparatively easy to grow and flower from seed.

C. aspera is one of the species without the long persistent leaf sheaths. It is fairly strong growing and the leaves are a light shining green some 3.5 cm to 5 cm long. They are covered with tiny raised bumps which look dark on the leaf, but if the plant is put in front of the light it can be seen that they are transparent. The dried leaf sleeves are only some 1.25 cm long. Like C. cigarettifera it is a winter grower.

In this last section, it is perhaps useful to add a bibliography from whence all the information in the complete series, apart from that gained from my own collection and experience, was gleaned. The line drawings were in the main, made from plants from my own collection.

References:

  1. W. Haage - Cacti and Succulents - Studio Vista, London, England.
  2. Jacobsen - Handbook of Succulent Plants - Bol. 3, Blandford Press.
  3. Dr. G. Schwantes - Flowering Stones and Mid-Day Flowers - Benn, London, England.
  4. Dr. G. Schwantes - The Cultivation of the Mesembryanthemaceae - Blandford Press.
  5. W. Shewell-Cooper - The A.B.C. of Cacti and Succulents - The English Universities Press.
  6. Vols. 1, 2, 3, 4 of The African Succulent Plant Society Bulletin.
  7. Vols. 20, 21, 23, 24 and 25 of The National Cactus and Succulent Journal.


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