Aerva hainanensis F. C. How, Acta Phytotax. Sin. 8: 343. 1963; Psilotrichopsis hainanensis (F. C. How) C. C. Townsend.

Herbs perennial, 20-30 cm tall. Stem erect, few branched, long yellow lanose above. Leaves opposite; petiole 5-8 mm, pilose; leaf blade elliptic to oblong, 4.5-10 × 1.5-4 cm, membranous, both surfaces strigose, base cuneate, apex obtuse and rounded, with a mucro. Spikes terminal, 0.8-2 cm, later arranged into short complex thyrsoid structures. Flowers small. Tepals 5, yellow, oblong, 2-2.5 mm, glabrous, with some veins extending to mucros. Stamens ca. 1 mm; filaments united to membranous cup below; pseudostaminodes triangular, very small. Ovary subglobose. Utricles compressed, ca. 1 mm. Seeds dark purple, reniform. Fl. and fr. Jul.

Psilotrichopsis curtisii var. curtisii occurs in Malaysia.

* Hillsides, riverbanks. Hainan.