Perennial herbs and soft-wooded shrubs; branches often very tough. Leaves alternate, usually obovate or spathulate, sessile, succulent, borne in terminal rosettes. Inflorescence a thyrse, usually with many monochasial branches; peduncle more or less scape-like, usually with widely spaced, leaf-like bracts. Sepals 6–12, fleshy, connate; petals 6–12, spreading, scarcely connate, yellow, white or pink; stamens usually twice as many as petals and adnate to their bases, in 2 whorls, often of unequal length, shorter than petals; carpels as many as petals, free, each with many ovules, each often with a basal scale-like nectary gland, style not differentiated, stigma ill-defined. Fruit a follicle; seeds many, very small, with longitudinal ridges, usually tuberculate.
About 40 species, mainly from the Canary Islands and adjacent north-west Africa; 2 species naturalised in Australia.