5. Trigonostemon thyrsoideus Stapf, Bull. Misc. Inform. Kew. 1909: 264. 1909.
长梗三宝木 chang geng san bao mu
Shrubs or treelets, 1-6 m tall; branches puberulent to glabrous. Leaves uniformly spaced; petiole 4-12 cm, glabrous, with 2 conical glands at apex; leaf blade obovate-elliptic or oblong-elliptic to lanceolate, [10.5-]16-32 × 3.5-12 cm, papery, both surfaces glabrous, brownish when dry, base broadly cuneate to rounded, margins obscurely sparsely glandular-serrate, apex acute to shortly acuminate; lateral veins 8-13. Inflorescences terminal, pyramidal thyrses, to 20 cm, brown pubescent. Male flowers: sepals 5, ovate, ca. 1.5 mm, exterior pilose; petals 5, oblong, yellow, glabrous, 3-4 × 1.8-2 mm; disk glands 5; stamens 5; filaments connate; connectives conspicuously produced, erect, emarginate. Female flowers: sepals and petals as in male, but larger; disk cupular, 5-lobed; ovary glabrous; styles 3, short, shallowly bifid. Fruiting pedicels ca. 3 cm; capsules ca. 1.5 cm in diam., deeply longitudinally 3-grooved, sparsely and very shortly aculeolate. Seeds ellipsoidal, with stripes of gray spots. Fl. Apr-Jul, fr. Jun-Sep.
Dense forests; 600-1000 m. Guangxi, Guizhou, S Yunnan [Laos, Myanmar, N Thailand, Vietnam].