白花三宝木 bai hua san bao mu

Trigonostemon leucanthus Airy Shaw; T. leucanthus var. siamensis H. S. Kiu.

Shrubs ca. 1 m tall; branchlets sparsely appressed pubescent to glabrescent. Leaves uniformly spaced; stipules small; petiole 2-5.5 cm, sparsely pilose to glabrous, apex with 2 subulate glands; leaf blade broadly elliptic, 9-16 × 3.5-6 cm, thinly leathery or papery, both surfaces glabrous, adaxially verruculose, base cuneate, margin entire or obscurely undulate-crenellate, apex acute to acuminate, rarely obtuse; basal veins 3, lateral veins ca. 6, delicate. Inflorescences axillary or terminal, panicles, to 21 cm, bisexual, bracts subulate, ca. 2.5 mm, villous. Male flowers: pedicel delicate, 3-7 mm, glabrous; sepals obovate, 1-2 mm, apex rounded, glabrous; petals broadly spatulate, ca. 3.5 × 2 mm, white, membranous, clawed, apex rounded; disk cupular, ca. 0.5 mm high; stamens 3; filaments connate for ca. 2 mm, free part to 0.5 mm. Female flowers: pedicels clavate, 1-1.5 cm, glabrous; sepals 5, ovate, ca. 3 mm, exterior sparsely villous; petals as in male, ca. 7 mm; disk cupular, ca. 0.5 mm high, margins undulate or entire; ovary glabrous; styles free, ca. 1 mm; stigmas bifid, divaricate. Fruiting pedicels clavate, to 2.8 cm; capsules ca. 1 cm in diam., glabrous. Seeds elliptic, ca. 6 mm in diam., brown with stripes of gray-white spots. Fl. Apr-May, fr. Jun-Aug.

Montane thickets; 500-600 m. S Guangxi [N Thailand].