Oxymitra gabriaciana Baillon, Adansonia 10: 106. 1871; Goniothalamus saigonensis Pierre ex Finet & Gagnepain.

Trees to 5 m tall, glabrous except for flowers. Petiole 5-8 mm; leaf blade narrowly oblong-lanceolate, 12.5-22 × 2-4 cm, leathery, midvein adaxially depressed, secondary veins obscure, base cuneate, apex obtuse. Inflorescences axillary, 1-flowered. Pedicel short, bracteolate at base. Sepals broadly ovate, outside puberulent, inside glabrous. Petals greenish; outer petals oblong-triangular, ca. 1.2 cm, hispidulous; inner petals ovate, ca. 1 cm, outside hispidulous, inside glabrous. Stamens oblong; anther locules longitudinally striate; connectives apically subcapitate, puberulent. Carpels cylindric, glabrous; ovule 1 per carpel, basal; styles terete; stigmas apically shallowly 2-cleft. Monocarps oblong-ellipsoid to ellipsoid, 1-1.8 × 0.5-0.8 cm, glabrous. Seed 1 per monocarp. Fl. May-Jul, fr. May-Nov.

Densely forested slopes; 300-800 m. Hainan [Cambodia, Laos, Thailand, Vietnam].