15. Trivalvaria (Miquel) Miquel, Ann. Mus. Bot. Lugduno-Batavi. 2: 19. 1865.
海岛木属 hai dao mu shu
Authors: Bingtao Li & Michael G. Gilbert
Guatteria sect. Trivalvaria Miquel, Fl. Ned. Ind., Eerste Bijv. 381. 1861.
Shrubs or small trees, indument of simple hairs, sometimes absent. Inflorescences extra-axillary or sometimes leaf-opposed, sometimes fasciculate on woody axes; flowers solitary or paired. Flowers polygamous or bisexual. Flower buds very broadly ovoid to cylindrical. Sepals 3, small, imbricate, free or united at base. Petals 6, in 2 whorls, unequal, each whorl minutely imbricate or valvate, outer petals spreading, inner petals larger, spreading or connivent and concave. Male flowers: torus conical, broadly conical-ovoid, or cylindrical; stamens many; connective apex shieldlike to tongue-shaped, minutely pubescent or glabrous. "Female" flowers: stamens few; carpels many, densely hairy; ovule 1, basal. Styles absent; stigmas ± globose. Bisexual flowers: torus cylindrical; stamens and carpels many. Fruit apocarpous; monocarps 2 to > 20, shortly stipitate, ellipsoid to oblong or ovoid, thin walled, glabrous or pubescent. Seeds solitary, ellipsoid to oblong, smooth, shiny, with circumferential, longitudinal groove.
Four species: Bangladesh, China, India, Indonesia, Laos, Malaysia, Myanmar, Thailand, Vietnam; one species in China.
Trivalvaria has not been recognized for China in previous Flora accounts, but see Heusden (Nordic J. Bot. 17: 169-180. 1997).