2. Bombax Linnaeus, Sp. Pl. 1: 511. 1753.
木棉属 mu mian shu
Deciduous big trees; young trunk usually spiny. Leaf blade palmately compound; leaflets 5-9, sometimes petiolulate, with basal joint, margin entire. Flowers bisexual, solitary or fascicled, axillary or terminal. Flowers large, produced before leaf flush. Pedicel shorter than 10 cm. Bracteoles absent. Calyx tubular, campanulate, or cup-shaped, apex truncate to deeply lobed, sometimes with abaxial glands, leathery, falling with petals and stamens. Petals 5, usually red, sometimes yellow, orange, or white, obovate or obovate-lanceolate, asymmetrical, sometimes reflexed. Stamens 70-900, bases connate into short tube; filaments connate into 5-10 distinct phalanges, alternating with petals; anthers reniform. Ovary syncarpous, 5-locular; ovules many per locule; style filiform, longer than stamens; stigma stellately lobed. Capsule loculicidally dehiscent into 5 valves, valves woody or leathery, with silky wool inside. Seeds small, black, enclosed by wool.
About 50 species: mostly in tropical America, also in tropical Africa, Asia, and Australasia; three species in China.