Leptopus australis (Zoll. & Moritzi) Pojark.

The variable and widespread Leptopus australis can be immediately distinguished from other species of Leptopus by its smaller stature, dense indumentum, short female pedicels, small orange-brown fruit, and often attenuate leaf bases. Leptopus australis is the only Chinese species of Leptopus with a deeply ridged seed. J. D. Hooker (Icon. Pl. 18: t. 1704. 1887) treated material of this species as Andrachne fruticosa.

Ascendant to erect herbs to subshrubs, 0.1-0.5 m tall, monoecious. Branchlets terete to flattened, light green to brown. Stipules triangular to subulate, base not auriculate, apex acute, ferruginous to almost black; petiole 5-20 × 0.5-0.8 mm; leaf blade ovate to lanceolate or obovate, (1.5-)2.5-7(-10) × (0.7-)1.2-2(-3.2) cm, membranous to thinly papery, drying discolorous to concolorous reddish to yellowish or grayish green, abaxially hirsute, adaxially glabrous to hirsute, base long attenuate to acute, sometimes obtuse, apex acute; secondary veins 4-6 pairs. Inflorescences unisexual or bisexual, male inflorescence axis 0-3 mm. Male flowers 1-4(-6) per fascicle, 1.5-2.5 mm in diam.; pedicel 4-8 mm; sepals obovate to oblong, apex rounded, 1-1.6 × 0.6-1 mm, eglandular; petals obovate to linear, apex rounded, 0.6-1.2 × 0.2-0.3 mm; disk bilobed for 4/5-5/6 of length. Female flowers 1-4 per fascicle, 3-6 mm in diam., rotate; pedicel 2-5 mm; sepals ovate to obovate or oblong, 1.5-3 × 1-2 mm, apex acute to cuspidate, eglandular; petals linear to obovate, 0.1-0.5 × 0.1-0.2 mm, apex rounded; disk bilobed for 1/2-3/4 of length; ovary 3-locular, densely hirsute; styles 3, glabrous to basally hirsute. Fruiting pedicel 5-9 mm; sepals accrescent to 2-6 × 1-3.5 mm; capsule smooth to faintly reticulate, hirsute, drying red-brown to orange-brown. Seed transversely to irregularly ridged, orange to brown.

Evergreen forest understories on sand or limestone. Hainan [India (Andaman Islands), Indonesia, Malaysia, Philippines, Thailand, Timor, Vietnam].

Andrachne australis Zollinger & Moritzi in Zollinger, Natuur- Geneesk. Arch. Ned.-Indië 2: 17. 1845; Agyneia tenera Zollinger & Moritzi ex Miquel; Andrachne australis var. angustifolia Müller Argoviensis; A. calcarea Ridley; A. hirta Ridley; A. lanceolata Pierre ex Beille; A. polypetala Kuntze; A. tenera Miquel; Leptopus calcareus (Ridley) Pojarkova; L. hirtus (Ridley) Pojarkova; L. lanceolatus (Pierre ex Beille) Pojarkova; L. philippinensis Pojarkova; L. polypetalus (Kuntze) Pojarkova; ?L. sanjappae Sumathi et al.; Thelypetalum pierrei Gagnepain.