Description from Flora of China
Celtis orientalis Linnaeus, Sp. Pl. 2: 1044. 1753; C. discolor Brongniart; C. rigida Blume; Sponia argentea Planchon; S. orientalis (Linnaeus) Decaisne; S. wightii Planchon; Trema polygama Z. M. Wu & J. Y. Lin.
Trees or shrubs, to 20 m tall, d.b.h. to 80 cm. Bark gray, smooth, irregularly fissured on old branchlets. Branchlets grayish brown, pubescent. Stipules linear-lanceolate, 5-9 mm. Petiole 0.8-2 cm, pubescent; leaf blade 10-18(-22) × 5-9(-11) cm, leathery and fragile, abaxially grayish white to grayish green when dry, pubescent, and surface completely hidden by hairs, adaxially green to grayish green when dry, ± scabrous, and usually rugate, base cordate and oblique, margin denticulate, apex acuminate to acute; basally 3-veined; secondary veins 4-6 on each side of midvein. Male inflorescences 1.8-2.5(-3.5) cm, pubescent. Female inflorescences 1-2.5 cm. Male flowers: 1.5-2 mm in diam.; tepals 5. Ovary rudimentary, obovate-conic, ± compressed. Female flowers: pedicellate; tepals 4 or 5, triangular-ovate, 1-1.5 mm. Drupes black when mature, ± globose to ovoid-globose, ± compressed, 3-5 × 2.5-3.5 mm, rugose; perianth persistent. Seed broadly ovoid, ± compressed, 2-5 mm in diam. Fl. Mar-May(-Jun), fr. Jun-Nov.
Trema polygama, described from Yunnan, differs in having the inflorescences shorter than the adjacent petioles.
Moist forests, dry scrub of open slopes; 400-1900 m. Fujian, SW Guangdong, W Guangxi, SW Guizhou, Hainan, Sichuan, Taiwan, Xizang, Yunnan [India, Indonesia, Japan, Malaysia, Myanmar, Nepal, Sikkim, Sri Lanka, Thailand, Vietnam; Australia, Pacific Islands].