Shrub or tree 5–10 m. Bark light or dark grey, somewhat rough with inconspicuous stripes. Branchlets reddish purple, slender, glabrous. Leaves deciduous, papery, 7–9 × 6–8 cm, palmately three-lobed, lobes half to two-thirds of the length, upper surface shiny and glabrous, lower surface usually glabrous, margins serru late, apex elongated, caudate to acuminate; petiole 3–5 cm long, slender, glabrous. Inflorescence terminal (and lateral), paniculate to racemose, slender with conspicuous bracts. Flowers 5-merous, staminate or hermaphrodite; sepals reflexed, linear to oblong, petals linear to oblong, purple, stamens 8–10, inserted in centre of nectar disc. Samaras 2.2–2.5 cm long, purplish yellow, wings spreading obtusely. Flowering May, fruiting September (China). Van Gelderen et al. 1994, Xu et al. 2008. Distribution CHINA: eastern Xizang, northwest Yunnan; INDIA: Arunachal Pradesh, Assam (?); MYANMAR. Habitat Alpine forest between 2400 and 3600 m asl. USDA Hardiness Zone 7–8. Conservation status Not evaluated. Illustration NT4, NT113. Cross-references B199, K109.
Discovered by Frank Kingdon-Ward in 1914, but introduced by George Forrest, this interesting species was placed in its own section by de Jong (van Gelderen et al. 1994). For decades it was represented in cultivation by a single tree at Trewithen in
Cornwall, but this was killed in the famously cold winter of 1962–1963, and although a cutting was reported to have been rooted from it (Bean 1976a), no specimens seem to have persisted. In recent years it has been reintroduced from western Yunnan, and young plants are now in cultivation at Tregrehan. It is evidently well adapted to its extremely wet native habitat, having long drip-tips on each of the three lobes of the leaves. The young plants have red shoots and a green main stem, and the mature tree is said to have a very ornamental weeping habit (Hudson 2004). How hardy these plants will be remains to be seen. In the Mishmi Hills of Arunachal Pradesh it forms thickets of shoots arising as suckers from the roots of older trees (M. Wickenden, pers. comm. 2007).