The genus Lithops contains 36 species (fifteen subspecies and thirty-six varieties), the name is derived from the Greek word lithos which means stone and opsis which means like, the genus got its name from the stone-like appearance of the plants.  Lithops are commonly referred to as beeskloutjie (cattle hoof), perdeklou (horse's hoof), stone faces and stone plants.

These dwarf nearly stemless succulents are partially subterranean, plants may have single or multiple heads (branched leaf pairs).  The leaf pair is fused and conical in shape with flat tops, these tops are marked or windowed.  Plant surfaces are smooth, rugose or covered with water cells.  The old leaf pairs eventually shrivel up and form sheaths which cover the new plant bodies.  A shallow fissure is present between the leaf pair.

Flowers are small to medium-sized, solitary (seldom appear in twos or threes), white, yellow or orange in colour.  Flowers appear on a short pedicel from the centre of the fissure.  The flower has four to seven petals, many petals which are arranged in one to four whorls.  Four to nine flimsy stigmas are surrounded by many stamens.  Fruit capsules are four to nine locular, covering membranes present or absent.  Seeds are variable in shape and size.
 

Plants are widespread in southern Africa (Namibia, Botswana, South Africa excl Natal).  The majority of species occur in the Nama Karoo, Succulent Karoo and seldom in semi-arid savanna regions.  Plants prefer gravely flats, stony ridges and hills that are made up of granite, quartz, shale, schist and limestone.  The average rainfall for the lithops distribution area is less than 500mm (some species occur in areas wth an annual rainfall of 100mm or less).