Lithops is a genus of succulent plants native to southern Africa. "Lithos" means "stone" and "-ops" means "face" in Ancient Greek; therefore "Lithops" means "stone-like". This is a very good description of these plants, which avoid being eaten by blending in with surrounding rocks. They are often known as pebble plants or living stones. The formation of the name from the greek "-ops" means that even a single plant is called a Lithops.
Individual Lithops plants consist of one or more pairs of bulbous, almost fused leaves opposite to each other and hardly any stem. The slit between the leaves contains the meristem and produces flowers and new leaves. The leaves of Lithops are mostly buried below the surface of the soil, with a partially or completely translucent top surface or window allowing light to enter the interior of the leaves for photosynthesis.
Lithops are obligate outcrosses and require pollination from a separate plant. Like most resembles, Lithops fruit is a dry capsule that opens when it becomes wet; some seeds may be ejected by falling raindrops, and the capsule re-closes when it dries out. Capsules may also sometimes detach and be distributed intact or may disintegrate after several years.
The most startling adaptation of Lithops is the coloring of the 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.