Didiereaceae

Abstract

Dioecious or gynodioecious cactus-like xerophytic shrubs and trees, mostly with marked dimorphism between long and short shoots, the former when young succulent, in age becoming more woody, the short shoots with spines and paired or rosulate leaves. Leaves alternate, simple, entire, deciduous; stipules absent. Flowers in thyrsic inflorescences with dichasial partial inflorescences, or fasciculate, unisexual, or perfect on some plants and pistillate on others, subtended by two median involucral bracts; tepals imbricate, two dimerous whorls; stamens (6−)8(−10), in one whorl, weakly adnate at the base to an annular nectary; anthers dorsifixed, tetrasporangiate, dithecal, and introrse; pistillate flowers often with staminodia and with an annular nectary; gynoecium paracarpous, (2−)3(−4)-carpellate, with a single style and a lobed stigma, and a solitary, basal, campylotropous, and crassinucellar ovule. Fruit dry, indehiscent, enclosed in the paired involucral bracts; seeds with a small funicular strophiole and a large curved embryo without endosperm and with scanty perisperm.