采木 cai mu

Trees, small, to 8 m tall, sometimes with spreading branches and shrubby. Trunk deeply sulcate. Bark light gray. Branchlets slender. Leaves 5-10 cm, shortly petiolate; leaflets 2-4 pairs, abaxially pale green, adaxially shiny, obovate to obcordate, 1-3 cm, papery, with fine veins, base cuneate, apex rounded or deeply emarginate. Racemes 2-5 cm, with several to numerous flowers; peduncles short. Pedicels 4-6 mm, slender. Calyx 3-4 mm; lobes oblong-lanceolate, apex acute. Petals yellow, narrowly obovate, 5-6 mm, apex obtuse. Stamens ca. as long as petals. Legume lanceolate-oblong, 2-5 × 0.8-1.2 cm; valves thin, with fine veins.

Cultivated in Guangdong (Guangzhou), Taiwan, Yunnan [native to Central America; widely introduced elsewhere].

The heartwood of this species is blood-red. Haematoxylin, ex­tracted from the wood and flowers, is an important dye used for mor­phological anatomy and pharmacological preparations. It is also used medicinally as an astringent for treating dysentery and diarrhea.