3. Leptopus hainanensis (Merrill & Chun) Pojarkova, Bot. Mater. Gerb. Bot. Inst. Komarova Akad. Nauk S.S.S.R. 20: 271. 1960.
海南雀舌木 hai nan que she mu
Andrachne hainanensis Merrill & Chun, Sunyatsenia 5: 102. 1940; A. hainanensis var. nummulariifolia Merrill & Chun.
Erect shrubs, 0.5-3 m tall, monoecious (often apparently dioecious). Branchlets terete, white to light brown, much lighter than leaves. Stipules triangular, base not auriculate, apex acute, almost black; petiole 1.5-4 × 0.3-0.4 mm; leaf blade ovate to elliptic, sometimes orbicular or obovate, (0.2-)0.4-1.5(-2) × (0.2-)0.3-0.8(-1.5) cm, thickly papery, drying slightly to strongly discolorous gray, dark red or brown, abaxially glabrous to sparsely hirsute, adaxially glabrous, base acute, sometimes obtuse or rounded, apex acute, sometimes rounded; secondary veins not visible or 2 or 3 pairs. Inflorescences unisexual, male inflorescence axis 0-3 mm. Male flowers 1-3 per fascicle, 1.5-2.5 mm in diam.; pedicel 1-2 mm; sepals obovate to oblong, apex rounded, 1.2-2 × 0.7-0.8 mm, eglandular; petals linear to narrowly obovate, 0.8-1.2 × 0.15-0.25 mm, apex acute to rounded; disk bilobed for 1/2-2/3 of length. Female flowers solitary, 3.5-6 mm in diam., rarely 6-merous, rotate; pedicel 7-14 mm; sepals rarely 6, obovate, 2-4 × 1-2 mm, apex obtuse to cuspidate, eglandular; petals linear, 0.2-1 × ca. 0.1 mm, apex acute; disk bilobed for 1/3-1/2 of length; ovary 3(or 4)-locular, hirsute; styles 3(or 4), basally hirsute. Fruiting pedicel 9-14 mm; sepals not accrescent; capsule smooth to faintly reticulate, hirsute, drying red-brown. Seed smooth, orange.
● Riverine forests. Hainan.
Leptopus hainanensis is easily distinguishable by its whitish stems, small leaves, and short male pedicels. It is most likely affiliated with L. chinensis.