8. Trigonostemon fragilis (Gagnepain) Airy Shaw, Kew Bull. 32: 415. 1978.
黄花三宝木 huang hua san bao mu
Poilaniella fragilis Gagnepain, Bull. Soc. Bot. France 72: 467. 1925; Trigonostemon lutescens Y. T. Chang & J. Y. Liang.
Shrubs ca. 1 m tall; young branches, petiole, and inflorescences uniformly densely spreading tawny pubescent, glabrescent. Leaves uniformly spaced; petiole 1-3 cm; leaf blade elliptic to oblong, 15-23 × 6-8.5 cm, papery, pubescent to glabrous on both surfaces, base broadly cuneate to rotund, margin entire or sparsely serrulate, apex acuminate, sometimes long acuminate; lateral veins 8-10. Panicles terminal, to 25 cm; bracts lanceolate, 3-5 mm. Male flowers: sepals 5, ovate, ca. 2 mm, exterior sparsely hairy; petals yellow, orange when dry, obovate, 3-5 mm, hooked; stamens 3. Female flowers: sepals lanceolate, 5-7, exterior pubescent; petals yellow, orange when dry, obovate-elliptic, ca. 8 × 4-5 mm, hooked; disk annular; ovary glabrous; styles 3; stigmas capitate. Capsules subglobose, ca. 1 cm, glabrous. Fl. Apr-May, fr. Jun-Aug.
Thickets on limestone; 500-600 m. S Guangxi, Hainan [Vietnam].