This page contains my collected knowledge about Lithops. I am no biologist or similar, so I don't know anything about genetics and all that stuff. But I've been growing and cultivating Lithops for a few years now and have had numerous different experiences, made mistakes and had successes.
Topics on this page:
General Information (Ger.: allgemeine Infos)
Annual rhythm (Ger.: Jahresrhythmus)
Reproduction (Ger.: Vermehrung)
Cultivation (Ger.: Anzucht aus Samen)
Look (Ger.: Aussehen)
Age (Ger.: Alter)
Pests and diseases (Ger.: Krankheiten)
Forms and Species (Ger.: Formen)
Nomenclature (Ger.: Namenvergabe)
Curiosities (Ger.: Kuriositäten)
Similar plants (Ger.: ähnliche Pflanzen)
General InformationLithops are leaf succulents that consist of two conjoined leaves, that are divided only in the middle by a small fissure. The whole plant is cone-shaped and the above-ground part is mostly round to minimize surface and thus evaporation.
Since Lithops come from the desert and are used to extreme heat and sun, they grow low and stay small. In very hot areas they even stay level with the ground to minimize evaporation even more.
In European climes they can grow taller, with too little light, however, they tend to become unnaturally long which leads to problems. If Lithops are cultivated in Europe (or rather: not in their natural clime) they should be given a very sunny place.
Adapted to their home they are extreme suvivalists. Lithops can, in extreme cases, survive without water for two years. If it doesn't rain, they are able to take in moisture from morning dew via their leaves. Because of their original hot habitat, they always take in as much water as they can get. They are unable to not take in surrounding water. In the desert this is no problem since there is not much water and if it rains, the water soon evaporates. The high succulence is much rather necessary for survival. On our windowsills, however, this can become a problem, especially when they are watered too heavily or too often, which leads to mould, bursting of the leaves and infections.
Lithops have their clorophyll on the inside of the leaves. The top surfaces are translucent or have windows to let light into the leaves. These windows can be large and continuous or small and divided by spots or lines.
Lithops have taproots that help them to reach water on deeper levels of the soil. If cultivated in too small pots or basins they push themselves up and out of the pot, expose their roots and sooner or later die.
Annual rhythmIf the Lithops had a sufficiently dry and cool period during the winter, it will start to flower again in the fall. Some lithops have white blossoms with a yellow center, but most Lithops have yellow blossoms. Only cultivars have blossoms in other colors like pink or orange. The blossoms will open during the early afternoon and close again in the evening, for three or four days in a row.
ReproductionLithops reproduce via seeds. After pollination of a blossom the plant grows a sead capsule in the middle of the fissure between the leaves. A seed capsule has 5 or more leaves (or whatever the correct name for this is) that open as soon as the capsule gets wet. Rain for example opens a seed capsule and washes out the seeds that get the necessary moisture for germination at the same time.
The seed capsule closes again as soon as it dries and so the seeds can stay safely hidden within for years. Lithops seeds can still germinate after many years.
Lithops cannot self-pollinate. Two different plants are needed to get seeds and it doesn't suffice to have a plant with two heads, each flowering. Two heads of the same plant share the same DNA and so usually cannot pollinate each other (there may be exceptions).
Because of the extreme living-conditions of Lithops it is very hard for them to reproduce. It doesn't rain often so existing seeds stay in the seed capsule for a long time. Seedlings are vulnerable to heat and draught and only with luck seedlings survive to become hardy plants. This is why Lithops have hundreds of seeds in one seed capsule. Even if all of them germinate, only a small part of them survive.
Lithops help themselves by having seeds with a very long lasting germination capacity but short germination time. Lithops seeds germinate within 2-7 days depending on the weather.
At a certain age Lithops tend to not only grow one new body each year but two or more. The plant does not really split itself but grows two heads on one root. Depending on the species Lithops can have up to 10 (aucampiae, hookeri, lesliei, marmorata and olivacea) or even up to 20 heads (salicola). The biggest known Lithops plant is a salicola with more than 350 heads.
Old and multi-headed plants can be split at the root but this is said to be difficult as one has to cut the root.
Growing Lithops from seeds at homeThe right soil
I usually use cactus soil mixed with aquarium sand for sowing Lithops. At first I used Sand from the nearby playground (sterilized in the oven) but now that was too much work so I switched to the already clean aquarium sand.
Both are possible, although I like the aquarium sand better. It doesn't make hard layers on top of the soil after being wet. Especially for the little Lithops seedlings this layer is not good. They can rip off their roots, when the top layer stays in position but the lower parts sink a little when drying.
These two ingredients are mixed with an approximate ratio of 1:1. If in doubt mix in more sand – they are desert plants after all. This mixture is fine enough so that the seeds won't fall too deep into it.
I also tried sowing Lithops on pure sand but since I only spray water on them in the beginning I had no possibility of giving them fertilizer and so they almost starved.
The cactus soil contains fertilizer and in this mixture it is just the right amount to keep the seedlings healthy and alive.
A few weeks ago I tried sowing Lithops on pumice stone. Someone at green-24.de suggested this to us and showed us pictures of many healthy seedlings in a pot full of pumice. But, my seeds do not seem to want to germinate on pumice stone. So I switched back to cactus soil and sand. Other mineral soils like Perlite, cocos humus and Seramis are definitely too chunky.
Lithops need light to germinate, so fine soil is very important.
The seeds are strewn onto the top of the soil and maybe pressed down a little. Since they are so very small, a single sowing is almost impossible. Professional gardeners sowing larger amounts use a saltshaker.
It is important to note, that Lithops seeds should not be watered from above. Too much water at once (as is inevitable when watering from above) will wash the seeds into the soil where they will get no light and will not germinate.
I always put a bit of Seramis in the bottom of the pots to manage a good drainage. On top of the soil I put a layer of sand, either before sowing or after the seeds have germinated. This keeps fungus gnats away. The seeds can be sown on the normal soil as well as the sand.
The pot is then covered with clear plastic wrap to ensure high moisture in the air.
As soon as the seeds have germinated (during spring this should take about 1 to 5 days), the plastic wrap can slowly be removed. And by slowly I mean for an hour or two the first day, a few hours more the next day and so on until it can stay off the whole time. Now it is high time to cover the top of the soil with sand, otherwise fungus gnats will happily move in. Covering the top of the soil with sand while the seedlings have already sprouted is precision work, because no seedling should be covered or buried under the sand.
Once most of the seeds have germinated and the seedlings have grown a bit, they should no longer be only sprayed with water. They have already grown very long (in comparison to their plant bodies) roots and will search for water in the lower parts of the pot. The best way to water them now is to dip the whole pot into a bowl of water (maybe with some fertilizer mixed into it) and to wait till the soil is soaked. But: don't drop the pot in the water!
After two to three months the soil may also dry out completely once in a while. The seedlings will then shrink a little, but once they are watered again, they will recover.
Best time to sow Lithops
The best time for sowing Lithops is spring or early summer. The seedlings have enough time to grow before the winter. Plants sown in autumn or winter have to survive the dark time of the year which leads to weak and extremely elongated seedlings and thus large losses.
Pots should in any case have holes in the bottom so that extra water can escape. Lithops are very sensitive to too much water and because of their long roots should be watered from below (via the pot saucer). The pots need to be deep enough for the long roots that grow quite early and even small seedlings can have roots three to four times the size of their bodies.
Almost anything matching these criteria can be used as a container for Lithops seeds and seedlings.
But the pots should be dark. In see-through materials algae develop which don't really hurt the young Lithops but may at some point become dominant in the pot.
Lithops not only need light to germinate, but also warmth. Temperatures should be between 20 and 25 degrees. My Lithops germinated wonderfully at a temperature of about 25 degrees (Celsius, by the way) but I know of quite a few people that Lithops germinate well neither with too low temps nor with too high temps. So somewhere in the middle should be optimal.
By the way, Lithops seedlings like to grow close together. As one can't control the sowing and with that the distances between the seedlings, they automatically grow in clusters.
This has a natural advantage: small and weak seedlings will not survive among the other seedlings and in the end only the healthy and strong seedlings stay alive.
Once the seedlings grow too big and start to shadow each other or push each other aside, they have to be repottet and isolated.
If too many seedlings have grown too close to each other it can happen that they push the ones in the middle slowly up. These seedlings will then be pushed out of the soil and can no longer get any water. In this case they have to be repottet and isolated a bit earlier.
The small seedlings already tolerate direct sun, but they should be kept out of the midday sun. If the seedlings are used to artificial light, they have to be given some time to get used to the stronger natural sunlight. If placed into the sun too early they can burn and die.
LookLithops have adapted to their natural surroundings perfectly. Their look helps them to stay inconspicuous and avoid being eaten by small animals. That's how they got their German name "living stones" because they look just like the stone lying next to them. In cultivation these characteristics are often shown by planting Lithops in a bowl and surrounding them with similar looking stones. This draws the attention of guests who wonder why there is a bowl with soil and some stones on it on your windowsill.
Some Lithops in their natural habitat in Africa are disguised in a way that keeps them only a bit above the soil and that makes them look like the surrounding terrain in color and texture.
For example like this: www.lithops.info/de/galerie/lithops_c393.html
Other Lithops surprise by being white in otherwise brownish surroundings. But there are some white stones around, so they have the same color as them and stay hidden this way. These are one example for such white Lithops: http://www.lithops.info/de/galerie/lithops_c239.html
I have often wondered how Lithops "know" how to look inconspicuously in their surroundings. Lately a nice member of green-24.de gave me the answer (thanks, Norbert). He told me that they originally didn't "know". That all kinds of Lithops grew in all kinds of desert surroundings. But after decades the ones that were plainly visible got eaten and had no chance to reproduce. So naturally only those Lithops survived in their surroundings that had the best camouflage.
AgeIt is hard - not to say impossible - to determine the age of a Lithops plant in its natural habitat. There are theories about the length of the roots saying something about their age but they are not well funded. The only possibility to determine age at the moment is to count existing dried up leaf hulls. Each year a new dried leaf hull is produced and if they are well preserved and didn't fall off they can be used to determine the age of the plant, at least roughly.
With this method plants could be found with the age of 50-95 years. In cultivation the oldest plant was at least 36 years.
The number of heads on a Lithops plant however is no sign of a certain age.
Pests and diseasesMealybugs like to sit in the space between the old dry leaves or in the fissures between the leaves once they have been pushed apart by a flower bud.
Rats and mice can become a danger to Lithops outside or in a green house because they like to gnaw on Lithops. Smaller injuries are no problem and vanish the next year with the new pair of leaves at the latest. Larger injuries can become a starting point for infections or mould. If the heart of the plant is damaged it will not grow a new pair of leaves the next year and die.
Birds and worms can be dangerous for Lithops, too. Birds might eat any part of a Lithops whereas worms eat the roots and the damage only becomes visible when it is already too late and no roots are left.
With Lithops seedlings fungus gnats and their larvae are the worst enemy. They like the moist soil and apparently Lithops seedling roots are especially tasty.
Damages done by fungus gnat larvae are suddenly visible when the little plants get glassy and then dry out and die. Often it is only then that the missing or severely damaged roots are discovered.
Remedies for and protection from pests and diseases
- Herbivores. If Lithops are cultivated outside or in a green house, rats, birds and other herbivores can be kept away by hanging nets or closing the green house doors in the evenings. Inside these animals are not a problem (apart from pets – cats for example like Lithops. However, not so much as food but rather as a cosy place to sleep... )
- Mealybugs can be defeated by regularly picking them off the plants. To prevent an infestation it can be helpful to remove old and dry leaves in spring and dried up flowers in autumn.
- Fungus gnats, if they're already there they are hard to fight. Neudomück by Neudorff seems to be a helpful remedy, but I have never tried it, especially not on Lithops seedlings.
Preventive measures are to prepare the pots in a certain way before sowing Lithops.
- Infections and fungi mostly appear if the plants have been hurt. Apart from herbivores and mechanical damages this can only happen if the Lithops have been watered too thoroughly or if they aren't getting enough light.
In case of over-watering the old leaves cannot dry out but the new ones start growing anyway. The old leaves will then be pushed apart and they rip creating wounds.
During the summer too much water will let the Lithops body swell too much and it rips open at the sides or the top. Lithops are extremely succulent which means that they cannot choose whether to take in water from the ground or not. If there is water, they have to take it in. These wounds are a point of entry for infections.
If the soil is constantly wet the roots can get mouldy.
Not enough light does not lead to infections and mould but it leads to elongated plant bodies (in search for light). Then the way through the middle may become too long for a new body in winter and it breakes through the old one on its side. The break through point again is a point of entry for infections and mould.
- Sudden death. Sometimes whole Lithops plants or single heads do not grow a new plant body during the winter. They will not flower in that year but they can survive like this for two or three years. Then they will dry out slowly and die. Why this sometimes happens is still not clear. Probably the heart of the plant, the place where the main growth takes place, has gotten damaged somehow and the plant has no chance at survival.
Forms and SpeciesThere are several points in which Lithops can be differentiated. Looking from above at the plant or looking from the side (through the soil) at the plant.
Lithops plants can have
- symmetrically round (almost elliptical) leaves
- asymmetrically round leaves
- elongated leaves
With symmetrically round forms the two leaves have almost the same size. Asymmetrically round forms have one leaf distinctly bigger than the other. The elongated forms can have both, leaves of equal or different size.
Pic 1: symmetrically round leaves, round form
The symmetrically round plants can have a round form as whole plant (still seen from above, but both leaves taken together - pic 1). These plants often look like stones with a shallow fissure carved in the middle.
Pic 2: asymmetrically round, individually round
The leaves can also appear round in themselves, looking like two stones of identical size next to each other (pic 2).
Pic 3: elongated leaves, symmetrical form
The elongated forms look as if a stone has been cut and pushed open (pic 3).
The symmetrically round plants can also combine the first two looks: on one side they are connected and look like one stone and on the other side they diverge and look like two separate stones (pic 4).
Pic 4: combination of symmetrically round and individually round
From the side:
Lithops plants can have a totally even surface or a round one. Some even have a concave surface.
The fissures between the leaves can be very shallow (mostly the ones with even surface have shallow fissures but sometimes also those with round surfaces). They can be a little deeper (mostly the ones with round surfaces). Or they can be very deep and prominent (the elongated forms).
Pic 5: even surface, shallow fissure
The plant bodies in themselves can be distinguished, too. They can be cylindrical, with the difference of longer or shorter forms.
Pic 8: cylindrical form, shorter
A separate form appears on multi-headed plants. Here the heads are all attached to the same root and so the outer heads have to stretch a little (a lot for plants with many heads) to stay connected with the root.
Pic 10: Lithops with several heads that bend to the side to reach from root to surface
The asymmetrically round form (pic 2) with even surface and mostly shallow fissure (pic 5):
Lithops aucampiae C002
The elongated form (pic 3), cylindrical (pic 8) with round surface and very deep fissure (here can be seen what I meant about the sliced stone):
Lithops divergens C201
The round form (from above, from the side and the surface) with a semi deep fissure:
Lithops dorotheae C124
Lithops from the inside and close up can be seen here: http://www.lithops.info/de/botanik/laengsschnitt.html
All other distinctive features depend on the species. There are Lithops...
And in addition to that there are the subspecies and varieties. All in all about 413 different Lithops are known.
NomenclatureThe name Lithops stems from the Greek "lithos" meaning stone and "opsis" meaning look.
Lithops is already plural, so there is no single "Lithop" just as there are not many "Lithopses".
It's simply Lithops.
Lithops are named the moment they are found by a scientist, biologist or botanist (or whom ever) and published in a scientific paper describing the plant and its affiliation with one of the subspecies and naming it.
The plants then get a Latin (botanical) name that is accompanied in correct writing by the name of the author (of the scientific article introducing it). For example:
Lithops N.E. Br. aucampiae L. Bol.
Where the latin names are printed italic or bold to distinguish them from the names of the authors. Here Dr. N.E. Brown who in 1922 has published the first article about Lithops and thereby created the genus (short N.E. Br.) and Dr. H.M. Louisa Bolus who has published the name aucampiae of the genus Lithops.
Even longer names like Lithops aucampiae ssp. Euniceae var. fluminalis are correctly called:
Lithops N.E. Br. aucampiae L. Bol. ssp. euniceae (H.W. de Boer) D.T. Cole var. fluminalis D.T. Cole
Every species and subspecies that was discovered by different people is annotated with different names. The name in brackets with the subspecies (short ssp.) declares the original author. Here H.W. de Boer has originally named the Lithops aucampiae var. euniceae that was then "upgraded" by Desmond T. Cole to Lithops aucampiae ssp. euniceae. So the first author appears in brackets and the second one behind.
Because this naming convention is very long and impractical (to write and to read) usually the authors are omitted and are only attached to avoid confusion if different synonyms for the same plant are used.
So the authors shall be of no further interest here.
But after what are Lithops named?
Three different things as it turns out.
1. The place (or the characteristics of the place) where they were found
2. Their look
3. Derived from the author's name or any other person.
aucampiae, bromfieldii, comptonii, fulleri, hallii, herrei, lesliei: named after the person who found them
optica, pseudotruncatella, divergens, olivacea: named after their look (optica = eye like, pseudotruncatella = looking like Mesemb truncatellum, divergens = diverging, olivacea = olive colored)
terricolor: named after the place where they were found (terricolor = earth colored)
gracilidelineata, marmorata: named after their surface (gracilidelineata = gracefully lined, marmorata = marbled)
Albiflora, Witblom, Fritz's White Lady: named after the anomalous white blossom on otherwise yellow flowering Lithops
And then there are Lithops named after other people than the author:
annae: named after the author's wife
helmuthii: named after the author's son
margarethae: named after the author's daughter
rushiorum: named after the whole family
naureeniae: named after the botanist's (in this case Desmond T. Cole's) wife (Naureen)
dorotheae: apparently named after a beautiful girl that had no interest in or knowledge about Lithops at all
(I have these infos from the book "Lithops – flowering stones" by Naureen and Desmond T. Cole)
Curiosities and abnormal growthLithops have one big advantage: because of their annual rhythm and growing new leaves each year they can get rid of injuries and scars easily.
If for example a Lithops plant is gnawed on by rodents but not completely eaten, it will regenerate during the next winter and start over with the next pair of leaves. The same is true for sunburn. Each new pair of leaves is like a new beginning for the plants.
Because of this fact abnormal growth is not that bad or even fatal for Lithops.
What kind of curiosities can occur?
The most common deformation often already occurring in Lithops seedlings are deformations of the leaves.
Seedlings often don't have a fissure reaching from one side to the other. While they are still young this may be normal but in older plants such fissures are not. This is easily explained: the plant will blossom in the fall and the flower bud will push the leaves aside. If the fissure is that small, the flower bud will most probably rip the plant open in order to grow out of it.
Other deformities include fissures reaching from one side to the middle of the plant but not through to the other side. Or even bending in the middle of the leaves to a different size (this then looks like a piece of cake being cut out).
A more common deformation are plants with 3-5 or more leaves. Since one head should always only have one pair of leaves, this counts as a deformity. Especially seedlings often have three leaves instead of two.
Usually this vanishes with the next pair of leaves, but sometimes a plant keeps growing three leaves over and over again. As long as this deformity does not keep the plant from flowering or growing new leaves it is no problem.
The true curiosities however have been described in the book „Lithops – flowering stones“ by Desmond T. Cole. He talks about a Lithops that was skewered by a blade of grass that obviously did not want to grow around the Lithops. Also a Lithops that had its roots not growing down but up and inward makes the list of the most curiously grown Lithops.
I have come across many people asking if what they have just bought is a Lithops. Unfortunately very often that is not the case. There are many plants that look similar to Lithops but aren't Lithops. For example: