Description from Flora of China
Potameia chinensis (C. K. Allen) Kostermans.
Trees, up to 20 m tall, to 24 cm d.b.h. Branchlets brownish, striate and lenticellate, rusty tomentulose when young but soon glabrate. Leaves opposite or alternate; petiole brownish, less than 2 cm; leaf blade glaucous abaxially, ovate or elliptic, 6-13.5 × 2.5-8 cm, leathery, finely pubescent abaxially and glabrous adaxially when young, glabrous on both surfaces or glabrate abaxially and glabrous adaxially when mature, midrib brownish, elevated abaxially, impressed adaxially, lateral veins 3-5 pairs, veins and veinlets densely reticulate and finely foveolate on both surfaces, base cuneate but always asymmetrical on sides, apex acuminate, acute, or obtuse. Panicle axillary, up to 4 cm, rusty tomentose, few flowered, shortly pedunculate. Pedicels short, ca. 1.5 mm. Flowers green-yellow, ca. 1.5 mm, rusty tomentose. Perianth lobes 4, ovate. Fertile stamens 4, slightly exserted, subsessile, outer 2 each with 2 glands at base; anthers 2-celled; cells introrse. Staminodes 4, opposite to fertile stamens, villous. Fruit turbinate, contracted into a short stalk at base, 3.5-4 × ca. 3 cm, ca. 1 cm in diam. at base, black-red when dry, glabrous; fruit stalk indistinctive from peduncle, including peduncle ca. 4 × 1 cm, rusty striate, glabrous. Fl. Apr-May, fr. Sep-Oct.
● Valleys, evergreen broad-leaved forests; ca. 500 m. S Hainan.