Description from Flora of China
Ulmus tonkinensis Gagnepain.
Trees, to 30 m tall, d.b.h. 40-80 cm, evergreen. Bark yellowish gray to chestnut brown, exfoliating in irregular flakes. Branchlets brown to red-brown, pubescent when young, ± pubescent with age, unwinged and without a corky layer, with scattered lenticels. Winter buds dark brown to red-brown, ovoid-orbicular, pubescent or glabrous. Petiole 2-7 mm, pubescent; leaf blade lanceolate, ovate-lanceolate, or narrowly orbicular-lanceolate, 3-10(-11) × 1.5-3.5 cm, thick, abaxially pea green and pubescent only near petiole or occasionally with a few hairs on midvein, adaxially lustrous green and pubescent only on midvein, base rounded or ± oblique and asymmetric, margin obtusely regularly simply serrate, apex acuminate; midvein depressed; secondary veins 6-18 on each side of midvein. Inflorescences fascicled cymes, 3-11-flowered. Flowers from floral buds. Perianth glabrous or margin ciliate. Samaras orange-brown, obovate, orbicular-obovate, or ± orbicular, strongly oblique, 1.2-2.8 × 1.2-2.1 cm, glabrous except for pubescence on stigmatic surface in notch; stalk shorter than perianth, glabrous or pubescent; perianth persistent. Seed at center or toward apex of samara. Fl. and fr. winter or early spring, rarely in autumn. 2n = 28.
Ulmus lanceifolia has been reported from Nepal (Hara et al., Enum. Fl. Pl. Nepal 3: 205. 1982), but this identity is uncertain.
300-1500 m. Guangxi, Hainan, Yunnan [Bhutan, India, Laos, Myanmar, Sikkim, Thailand, Vietnam].