7. Bixaceae
红木科 hong mu ke
Authors: Qiner Yang & Michael G. Gilbert
Shrubs or small trees. Young branches and leaves with peltate scales. Leaves alternate; stipules small, sheathing bud, fugacious; petiole swollen at base and apex; leaf blade simple, palmately veined. Inflorescence a terminal panicle. Flowers bisexual, actinomorphic. Sepals 5, free, imbricate, with basal, abaxial glands, fugacious. Petals 5, imbricate, large and conspicuous. Stamens many, free or slightly united at base; anthers oblong, with 2 inverted, U-shaped thecae, dehiscing by short, apical slits on bend. Ovary superior, 1-loculed; ovules many on 2 parietal placentas; style slender; stigmas 2-lobed. Fruit a capsule, loculicidally 2-valved, usually spiny. Seeds many; testa red, slightly fleshy; embryo large; cotyledons broad, incurved at apex; endosperm copious.
One genus and five species: native to tropical America; one species widely cultivated in tropical regions, including China.
Molecular data suggest that the genus Diegodendron Capuron, endemic to Madagascar, is related to Bixa and could be included within the Bixaceae.
Zhang Pengyun & Zhang Yaojia. 1990. Bixaceae. In: Li Hsiwen, ed., Fl. Reipubl. Popularis Sin. 50(2): 180.
