Shrub or tree to 8 m, or more in cultivation. Bark pale or dark grey, smooth. Branchlets yellowish-green to olive-brown, slender, glabrous and with round, raised lenticels. Leaves deciduous, thin and papery, tremulous, 4–6 × 3–6 cm, occasionally larger, palmately 3– to 5-lobed, rarely entire, lobes shallow, upper surface dull dark green and glabrous, lower surface pale green with some caducous hairs along the veins, margins entire, apex acute or rarely acuminate; petiole 3–8 cm long, slender, pale green or reddish, exudes milky sap when broken; autumn colour yellow. Inflorescence terminal, corymbose, 1.5–2 cm long. Flowers 5-merous, staminate or hermaphrodite; sepals oblong to ovate, pale green, petals oblong-obovate, yellowish-green, stamens 8–10, inserted outside the nectar disc. Samaras 2–2.2 cm long, purple when young, wings spreading nearly horizontally. Flowering in May, fruiting in September (China) (van Gelderen et al. 1994; van Gelderen & van Gelderen 1999; Xu et al. 2008; Gregory, in prep).
Distribution China Western Hubei, Jiangxi, Sichuan, Yunnan.
Habitat Mixed forest between 1200 and 1800 m asl.
USDA Hardiness Zone 6-7
RHS Hardiness Rating H5
Conservation status Endangered (EN)
Acer tenellum is rare in cultivation, and dismissed by van Gelderen & van Gelderen (1999) as being of ‘botanical interest only’. Despite this it is represented in a number of British and European collections, including Arley Castle, Worcestershire, and Borde Hill, West Sussex, probably grown from seed collected by Wilson in 1901 (van Gelderen et al. 1994). The identity of a tree at Glasnevin is the subject of debate. There is also some doubt over the authenticity of material offered commercially in the United States (Hill & Narizny 2004). Vegetative propagation is difficult, but it is available from nurseries specialising in Acer. Its charm lies in its small, rather rounded leaves, said to quiver in the breeze like those of an Aspen (Populus tremula). (van Gelderen & van Gelderen 1999).