1. Bixa orellana Linnaeus, Sp. Pl. 1: 512. 1753.
红木 hong mu
Shrubs or small trees, evergreen, 2-5(-10) m tall. Branches brown, densely red-brown glandular hairy. Petiole erect, 2.5-5 cm, glabrous; leaf blade abaxially pale green, with resinlike gland dots, adaxially deep green, cordate-ovate or triangular-ovate, (5-)10-25 × (3.3-)5-13(-16.5) cm, palmately 5-veined, glabrous, base rounded or subtruncate, sometimes slightly cordate, margin entire, apex acuminate. Panicles robust, often flat-topped, 5-10 cm, densely red-brown scaly and glandular hairy; bracts caducous, leaving scalelike scars. Flowers 4-5 cm in diam.; pedicel 4-12 mm. Sepals obovate, 8-10 × ca. 7 mm, densely red-brown scaly, with glands at base. Petals bright pink, mauve, or white with pale red veins, obovate, (1-)1.5-3 × 0.8-2 cm. Stamens many; anthers yellow, apically dehiscent. Capsule subglobose or ovoid, slightly laterally compressed, (1.4-)2-4.5 cm, usually densely purple-brown spiny, rarely smooth; spines 1-2 cm. Seeds numerous, red-brown, obovoid-angular, 4-5 mm.
Cultivated, tolerant of poor soils but intolerant of shade. Guangdong, Taiwan, Yunnan [native to tropical America; cultivated pantropically].
Bixa orellana is cultivated for the red, oil-soluble pigment, bixin, which is contained in the seed coat. It is used commercially as a food colorant and as a fabric dye. A paste prepared from the seeds is used as a skin paint (a common name is "lipstick tree") and as a condiment. Other parts of the plant are widely used in tropical America for a variety of medicinal purposes.