Heterostemma grandiflorum Costantin

Lianas to 5 m. Stems and branchlets longitudinally striate; internodes usually pubescent along 2 lines, sometimes glabrous. Petiole (2-)2.5-6.5 cm, flattened; leaf blade ovate or ovate-oblong, (7-)10-19 × (3.5-)5-10.5 cm, papery, glabrous, base rounded, sometimes truncate, apex obtuse or acute; basal veins 3, lateral veins 3 or 4 pairs, flattened adaxially, elevated abaxially. Inflorescences forked, 6-9 cm; peduncle 0.9-2.5(-3) cm. Pedicel 1-1.5(-4) cm, puberulent. Sepals ovate, margin membranous, ciliate. Corolla rotate, puberulent outside, glabrous inside; lobes ovate, ca. 4 × 3.5 mm. Corona lobes ligulate, ca. 3 mm, spreading horizontally and flat on corolla. Follicles linear-lanceolate, 10-12 cm × 7-10 mm, ± reflexed. Seeds broadly ovate, ca. 2 × 1.2 cm; coma ca. 2.5 cm. Fl. Jul-Sep, fr. Oct-Dec.

Open woodland, thickets. Guangdong, Guangxi, Hainan, Sichuan, Yunnan [Vietnam].