Lithops are little, intriguing plants native to southern Africa that are rather simple to grow inside. William John Burchell made the initial discovery of the Lithops in 1811 while on a botanical expedition in southern Africa. He came uncovered a strange-looking brown stone with a fracture running across its surface while exploring the Northern Cape Province, not far from the town of Prieska. This odd-looking stone proved out to be a succulent plant upon closer investigation. Due to their resemblance to stones, these members of the Mesembryanthemaceae (Aizoaceae) plant family were given the names lithos and opsis. Because they resemble tiny hoofprints, these plants are called locally by the Afrikaans names beeskloutjie (cattle hoof), skaappootjie (sheep hoof), or perdeklou (horse’s hoof). Even for those with a trained eye and years of experience, it can be challenging to spot Lithops in their native habitats in Namibia and South Africa because they have evolved to blend in so well with their surroundings—looking exactly like the sand and stones they live among in shape, size, and color.
Lithops are found in dry locations in colonies that are widely spaced apart and poorly populated. The word has both a singular and a plural form. In regions where Lithops are found, there is often less than 20 millimeters of rain per year, with the majority falling in the spring and fall. A few species rely on mist or fog as their primary supply of moisture, and some are found in regions with an average annual rainfall of four or less. They can grow on quartz grit or gravely flats, stony ridges and hills of sand, decomposed granite, quartzite, shale, schist, and limestone, as well as in many different types of environments. The Nama Karoo and succulent Karoo are home to the vast majority of Lithops species, which are particularly prevalent along the Orange River basin in the Northern Cape, which spans between Namibia and western South Africa.
Due to their ability to store water, virtually the entire plant of lithops is devoted to this purpose, they may survive in these dry places. Each plant is made up of two succulent leaves that have been fused together to form an inverted cone (although some species will produce multi-headed plants). The separation between the two leaves is represented by the fissure at the plant’s top. The taproot unites abruptly at the base of the leaves; there is no stem. The plants can go months without rain because to their large, water-storing leaves. They shrivel and shrink below the soil level during dry spells (nearly always).
These tiny succulents, which have almost no stems, are partially underground. In their natural habitat, plants only reach heights of 1/2 to 1 and widths of 1 to 3 inches, growing flush with the ground. The effects of the strong heat and sunlight where they live are reduced by remaining small and maintaining a low profile. However, this also creates a challenge in illuminating the leaf cells’ subterranean chlorophyll, which is used for photosynthetic activity. Wide leaf tips have windowed cells that allow light to enter the interior of the leaf, where it is diffused before reaching the chlorophyll, which is dispersed throughout the interior leaf edges, in order to resolve this paradox.
There are at least 37 species of Lithops, and more than 145 different variants have been identified. Although they all appear relatively similar to one another, they differ largely in terms of body shape, patterns, color, and texture. They are available in several soft shades of gray, brown, rust, green, and pink. The patterns of dots, lines, or patches on the upper surface, which aid in their ability to replicate their surroundings, vary considerably. Where the markings occur, there can also be dimples or indentations. The windows may completely enclose most of the leaf surfaces or the marks may densely cover the leaf surface.
The majority of Lithops bloom in the late fall and early winter, giving out numerous-petaled daisy-like yellow, pale orange, or white blooms. On sunny days, the blooms bloom in the afternoon and close again in the late afternoon. The crack between the leaves is where the flowers appear. There are perfumed flowers. Depending on the species and circumstances, they can be anywhere between 1/2 to 11/2 inches in size.
Because lithops are self-sterile, pollination is required to create seed. The hydrochastic 4–8 chambered fruiting capsule, which protects the seed, only opens when moistened, revealing the tiny seeds. In the natural world, raindrops splash out seeds up to a few feet or up to an inch from the parent plant. Any seeds still inside the capsule are protected until the following rain when the capsule closes after drying.
Following flowering, the plant enters a dormant stage during which at least one new body grows. As the new leaves emerge in the spring, the plants begin to reabsorb the old ones. Eventually, the crack between the old leaves is where the new body emerges. The new leaves’ fissure forms at a roughly 90-degree angle to the existing fissure. The old leaves eventually decompose into a dry, papery sheath on the side of the new body. At this point, a lot of plants will also divide to create many leaf pairs, which will eventually cause a single body to resemble a little cluster.
Lithops are common novelty houseplants because they can survive in low humidity, require little maintenance and water, and are reasonably simple to grow. These plants don’t require much space due to their modest size and sluggish, compact growth. Lithops live for 40 to 50 years on average. A plant can easily be kept in the same pot for ten or twenty years. Lithops are not harmful to people or animals. (Some references even mention African youngsters consuming these plants to relieve their thirst.) In cultivation, their health is reliant on adequate bright light, effective soil drainage, and appropriate watering.
Although a greenhouse is recommended, lithops can be grown effectively on a sunny windowsill where they get about 4 to 5 hours of direct sunlight in the morning and some shade in the afternoon. The optimum site is typically a southern window, while an unobstructed eastern exposure is a fine alternative. A plant will start to grow elongated and skinny, lean to one side to get more light, lose color and turn greenish, and eventually die if better circumstances are not provided. However, take care when transferring a plant suddenly to a brighter location. It could suffer deadly injuries from sunburn.
Similar to cactus, lithops demand well-drained soil. Use specialized cactus potting soil or add sharp sand, perlite, decomposed granite, or other grit to standard houseplant potting soil to help with drainage. These plants require a larger container than their apparent size would suggest because of their enormous root systems. To provide the roots enough room to expand, pots with drain holes and a depth of 3 to 5 inches are advised. Instead of having the plant’s top directly on the soil’s surface as it would in nature, place it just a little bit above it. For a more natural appearance, several growers topdress the plant with gravel or surround it with stones. Lithops go through a yearly cycle of growth, and it’s important to water them just when necessary and let the soil dry up at other times. The main factor contributing to early death is overwatering. They decay or grow new bodies at the incorrect time of year when there is too much water present. They grow stunted if there is little water. Depending on how rapidly the potting media dries out, you need to water more frequently. Generally speaking, water the plant and let it air dry fully (probably 1-2 weeks). After that, wait a few more days before watering once more. If unsure, don’t! The optimum time to water is in the morning because this allows the extra water to drain and the top soil layers to dry off pretty fast. Here are some general watering recommendations (however species may affect them slightly):
- from late spring to summer, water.
- Stop watering the plant in the summer when it turns dormant. Only water until the top half inch of the soil is moist if the plant truly starts to shrivel. This will restore the plant’s firm appearance.
- Watering should be resumed in late summer or early fall when plants begin to develop and bloom again. When the slit between the leaves starts to open up in anticipation of flowering, that is the first indication of growth.
- Lithops need to be completely dry during the winter and spring. Stop watering the plant so that the old leaf pair can dry out and make way for the new pair. The new body should be discernible by early April. Once the remains of the previous body have totally dried out and shriveled, watering can be resumed. The plant won’t grow properly if water is given too soon since the old “leaves” will want to continue to grow. Keep in mind that when the new leaves are developing, the old ones should completely dry out.
Fertilize Use a low nitrogen, high potassium kind of lithops. Lithops can withstand extremely high temperatures provided there is sufficient abundance of fresh air. Don’t ever let the plants freeze.
Today, specialty succulent nurseries sell seeds, plants, and a wide variety of cultivars. They sprout from seeds swiftly, and under ideal circumstances, they can be anticipated to flower in 3 to 4 years. The seeds should be sown on sandy soil during the summer and covered with a very thin layer of fine sand. Water the small seeds sparingly to avoid moving them. Keep the contents damp but not soggy and place the container in a warm, sunny location. In a few weeks, the first seeds should begin to sprout (but germination may be spread out over a long period of time, with stragglers taking as long as a year). Once the seedlings are growing quickly, watering should be reduced such that the upper 1/4 of the medium dries out and the lower 1/4 remains moist. Water sparingly during this time because too much watering could dampen off the seedlings. Start allowing the plants totally dry out for a few days between waterings when they are 2 to 3 months old, and then gradually extend the drying period. When the baby plants are around a year old, they can be transplanted. Another way to multiply lithops is to divide a multiheaded plant. Lift the plant, make a clean incision through the roots, and then quickly replant it. University of Wisconsin-Madison student Susan Mahr