丝胶树 si jiao shu

Kickxia elastica Preuss, Notizbl. Königl. Bot. Gart. Berlin 2: 353. 1899.

Trees to 35 m tall. Trunk to 50 cm in diam.; bark greenish brown to gray. Petiole 0.5-1.5 cm; leaf blade oblong or narrowly so, 6-27 X 1.5-10 cm, leathery, margin undulate; lateral veins 7-11 pairs, with axillary domatia abaxially, glabrous. Cymes short, glabrous; peduncle ca. 1 cm. Pedicel 2-8 mm. Sepals 4-5 mm, elliptic to broadly ovate, glabrous, glandular adaxially. Corolla tube pale green to white, 7-9 mm, glabrous; lobes 5-6 mm, apex obtuse. Anthers appressed pilose abaxially. Follicles narrowly spatulate, 8-19 cm, woody. Seeds fusiform, 4.5-7 cm, beak 3-5 cm, coma 4.5-7 cm. 2n = 22.

Cultivated in S Yunnan [native to tropical Africa from Senegal to Tanzania]

A valuable source of rubber.