Description from Flora of China
Trees ca. 20 m tall. Young branchlets puberulous. Leaves opposite, usually clustered at apex of branchlets; petiole 1-1.5 cm; leaf blade elliptic-oblanceolate or long elliptic, 7-15 × 3-5 cm, thinly leathery, abaxially puberulous or glabrous, adaxially glabrous, lateral veins in 8-12 pairs, base cuneate, margin entire, rarely dentate, apex acute. Bracts linear, small. Pedicel 3-4 mm, puberulous. Calyx tube puberulous; lobes ovate-triangular, minute. Petals white, linear, ca. 1 cm, apex acute. Stamens shorter than petals. Ovary pubescent. Style shorter than or subequaling corolla. Berry black when dry, ovoid, ca. 1 × 0.7 cm.
The Chinese Polyosma is very similar to P. integrifolia Blume (from W Malesia to Thailand and Vietnam), but differs from that species in having leaves narrower, usually less than 5 cm wide (vs. (4-)5-11 cm wide), pedicels longer, to 4 mm (vs. 1.5-2 mm), secondary veins not prominently looping near the margin, and fruit smaller, ca. 1 × 0.7 cm (vs. 1-1.8 × 0.7-1 cm). The Chinese plants may fall within the range of variation of P. integrifolia, but the present authors cannot be certain with the limited data and materials available to them. Therefore, the name P. cambodiana is retained for the time being. Further study is also needed to compare the Chinese plants with Polyosma in Indonesia.
Mountain rainforests, evergreen forests; 1000-2400 m. ?Guangdong, Guangxi, Hainan, S Yunnan [Cambodia, Thailand, Vietnam].