Microtropis tetragona Merrill & Freeman

Small trees or shrubs; branchlets obviously tetragonal, purplish brown. Petiole 5-10 mm; leaf blade rectangular-elliptic or narrowly ovate-elliptic, 8-13 × 2.5-5 cm, papery or thinly leathery, rarely falciform-acuminate, base cuneate, apex acuminate; secondary veins 6-9 pairs, slender, obliquely arching upward, closed on margin. Cymes 3-7-flowered, rarely more, loose, spreading; peduncle fine, 5-11 mm, secondary peduncle 3-5 mm; pedicels 1.5-3 mm. Flowers 5-merous; sepals semiorbicular; petals rectangular-elliptic or slightly broadly ovate-elliptic. Disk thin, annular, shallowly 5-lobed or entire. Stamens small and short; filament very short and conspicuous. Ovary broadly triangular-ovate; style often 4-lobed. Capsule nearly oblong, ca. 2 cm × 8-9 mm, apex often with short rostrum; valves abaxially finely angulate. Fl. Aug-Oct, fr. ca. Oct-Nov.

S Guangxi, Hainan, SE Xizang, SE Yunnan.

● Mossy evergreen forests, streamsides; 1000-2100 m.