Lithops is a genus of succulent plants native to southern Africa. They avoid being eaten by blending in with surrounding rocks. They are often known as pebble plants or living stones. The plants consist of one or more pairs of bulbous, almost fused leaves opposite to each other, with hardly any stem. The slit between the leaves produces flowers and new leaves.
The leaves are not green as in almost all higher plants, but various shades of cream, grey, and brown, patterned with darker windowed areas, dots, and red lines. The markings on the top surface disguise the plant in its surroundings. During winter a new leaf pair, or occasionally more than one, grows inside the existing fused leaf pair. In spring the old leaf pair parts to reveal the new leaves and the old leaves will then dry up.
Yellow or white flowers emerge from the fissure between the leaves after the new leaf pair has fully matured, one per leaf pair. Some species have flowers large enough to obscure the leaves. They open in the afternoon and close in the evening. In tropical climates, Lithops can be grown primarily in winter with a long summer dormancy.
Lithops are popular novelty house plants and many specialist succulent growers maintain collections. Seeds and plants are widely available in shops and over the Internet. They are relatively easy to grow if given sufficient sun and a suitable well drained-soil.