lebende Steine

In Lithops, an individual plant body, corpusculum or head consists essentially of two opposite leaves which (...) have become thickened, fused together along the outer edges, and foreshortened, so as to form an obconic, turbiniform (top-shaped) body. This is like an inverted cone, tapering down to the point of junction with the root, and with a fissure across the top, dividing it into two more or less equal halves or lobes (...) In most species the lobes are fused together along their outer edges to a depth of 1-4 mm, according to the size of the plant, but there is only a very thin line of adhesion closing the fissure across the top. Below this the cleft extends downwards, between the closely adpressed inner surfaces of the lobes, to the meristem or growing point immediately above the junction of the plant body with the root. When the plant flowers, the bud breaks through the thin line of adhesion in the middle of the fissure, thus opening the cleft (...)

(Desmond T. Cole, Naureen A. Cole: Lithops - Flowering Stones, p. 15)