The series on mimicry and deception written by Taisha continues. She scribes:
Members of the genus Lithops are known as the living stones. Most of the genus is found in arid areas of southern Africa, with Lithops dorotheae occurring near Pofadder, an area in the Northern Cape of South Africa. Lithops dorothea grows among fine-grained sheared quartz feldspar and feldspathic quartzite. Species of Lithops mimic the stones of their natural habitat in order to avoid herbivores. In the case of Lithops dorothea, the foliage is therefore reddish- or yellowish-brown, with some white to match the feldspar and quartzite. Camouflaging to reduce the rate of detection by antagonists is termed crypsis (Daniel: see some quoted material on crypsis below in the comments).
Morphologically, plants of Lithops (link contains illustration) are composed of a root and the plant body (aka corpusculum or head). The body is made up of two opposite leaves that are thickened and fused together, with a fissure down the middle. On the aboveground surface of the leaves, transparent or translucent windows permit light to penetrate deeply into the photosynthesizing parenchyma tissue of these CAM plants. The exposed area of the two leaves is collectively referred to as the face, and many variations exist amongst the genus in shape, texture and colour. The remainder of the conical plant body resides underground, presumably as an additional means of avoiding herbivores as well as protecting the plant from dessication.
Lithops are perennial species which undergo an annual cycle of growth, flowering and decline. Each year, a flower bud will develop below ground then break through the cleft of the two leaves to bloom. The seeds produced are in an specialized capsule that lacks a covering membrane. The capsule is closed to protect the seed during arid conditions, but will open during a rainfall to release the seeds. After flowering, the plant undergoes a dormant period where the body shrivels. Growth of a new body is eventually initiated, with nutrients extracted from the old body. The dried body of the old plant surrounds the new growth. After some rainfall, the new body will burst through the remainder of the old one, with the new pair of leaves’ fissure 90 degrees from the previous pair.