Tree to 30 m, dbh 1 m; branches rather pendulous. Bark light brown, mostly smooth but can be warted. Branchlets brown with a dense covering of yellowish brown pubescence, though often glabrous with age; at maturity, bark greyish white. Stipules lanceolate, to 0.7 cm long, caducous. Leaves deciduous or rarely evergreen, immature growth pinkish red, 5–13 × 2.5–5.5 cm, ovate-elliptical to oblanceolate, papery, upper surface glabrous, lower surface with inconspicuous yellow pubescence limited to the veins, later glabrous, three to four secondary veins on each side of the midvein, margins entire or serrate, apex acuminate to caudate; petiole with a broad furrow, 0.6–1.3 cm long, brown and glabrous or slightly pubescent. Flowers arranged in densely clustered cymes, or rarely in racemes of two to three. Infructescences unbranched or rarely forked, one to three per leaf axil; slender, glabrous or pubescent, 0.8–1.5 cm long. Fruit 0.7–0.8 cm diameter, orange-yellow. Flowering March to April, fruiting September to October (China). Fu et al. 2003. Distribution BANGLADESH; BHUTAN; CHINA: western Guangxi, Hainan, Sichuan, southern Xizang, central, eastern and southern Yunnan; INDIA; INDONESIA: Java and the Lesser Sunda Is., Sumatra (?); MYANMAR; NEPAL; TAIWAN; THAILAND; VIETNAM. Habitat Mixed, mesophytic forest in valleys and on slopes, between 700 and 1500 m asl. USDA Hardiness Zone 7–8. Conservation status Not evaluated. Illustration Lancaster 1989, Fu et al. 2003; NT232, NT233. Cross-reference B570 (as C. labilis).
During his trip to Yunnan in 1981 Roy Lancaster was greatly impressed by magnificent trees of Celtis yunnanensis growing in the grounds of the Great Flower Monastery in the Western Hills near Kunming. He commented that the species was then unknown in the West (Lancaster 1989), but that it was very distinct by virtue of its acuminate leaves. These are indeed a conspicuous feature on the few trees observed in research for the current work, and as they are also a glossy dark green with strongly impressed veins they are rather handsome.
The taxon grown since 1908 at Kew from Wilson 444, and described by Bean (1976a) as C. labilis, has more recently been identified as C. tetrandra. A re-propagation from 1965 was 8 m tall in 2001 (TROBI). Although this species is established in North American collections it has yet to become widely distributed. At the Morton Arboretum one specimen has formed a rounded, low tree of about 7 m, producing heavy horizontal limbs from upright stems. It seemed to be in poor health when seen in 2006, with a sparse canopy of rather pale leaves. This specimen, and others in the same collection, were grown from seed received in 1927 from the Istituto dell’Orto Botanico della Università in Rome, distributed as C. trinervia (a name applied by three different authors). There is a vigorous young tree at the JC Raulston Arboretum (labelled C. yunnanensis), 5 m tall in June 2006, grown from seed collected in Black Dragon Park in Lijiang, Yunnan in 1999 by Todd Lasseigne.