(genus Lithops) any of a group of about 40 species of succulent plants of the carpetweed family (Aizoaceae), native to southern Africa. The plants are virtually stemless, the thickened leaves being more or less buried in the soil with only the tips visible. Two leaves grow during each rainy season and form a fleshy, roundish structure that is slit across the top. Flowers grow between the slit, and then a shoot (with two leaves) grows from the axils of one or both of the leaves, which then shrivel. Living stones spread sideways, and one plant may have the appearance of several stones. They are cultivated worldwide as indoor plant curiosities.