Crassulaceae

Crassulaceae, an order of Calyciflorae (q.v.) allied to the Saxifragaceae (q.v.) and comprising some 400 to 500 species in 24 genera. They are characterised by their thick succulent leaves, being adapted to dry climates and situations, such as rocks, walls, and sandy plains, and are especially abundant in South Africa. Their flowers are in complex cymes, often dorsiventral, and are remarkably polysymmetric and pentamerous, having often five carpels as well as five sepals, five petals, and ten stamens. The fruit is a ring of follicles. Astringent roots, acrid foliage and emetic and purgative properties occur in the order. Though the genus Crassula is mainly African, some ten species of Sedum, the stonecrops, and single species of Tillaea, Cotyledon and Sempervivum are natives of Britain.