Description from Flora of China
Trees to 20 m tall. Bark dark brown, smooth. Branchlets purplish or purplish green, glabrous; winter buds purplish. Leaves deciduous; petiole purplish red, 2-7 cm, glabrous or densely rufous pubescent when young; leaf blade abaxially pale green, adaxially dark green, suborbicular, 7-10 × 6-8 cm, 3- or 5-lobed, papery, abaxially pubescent especially on veins or densely rufous pubescent on veins when young, adaxially glabrous, primary veins 5, lateral veins 8 or 9 pairs, base cordate, deeply cordate, or subcordate, 3- or 5-lobed; middle lobe ovate, apex caudate-acuminate, acumen ca. 1 cm; lateral lobes triangular, margin serrate, apex caudate-acuminate or obtuse. Inflorescence terminal on leafy branchlets, appearing after leaves develop, racemose, 6-8 cm, 10-40-flowered. Pedicel 5-7 mm, slender, glabrous. Staminate flowers: sepals 5, purplish green, oblong, ca. 5 mm, glabrous, apex obtuse; petals 5, obovate, apex obtuse; stamens 8, ca. 2 mm, glabrous; disk glabrous, intrastaminal; ovary rudimentary. Fruit yellowish; nutlets flat, ca. 7 × 4 mm; wing falcate, including nutlet 1.6-2.5 cm × 6-8 mm, wings spreading obtusely to nearly horizontally. Fl. Apr, fr. Sep.
After publication of the treatment in the FOC, it was discovered that Acer pectinatum is a nom. illeg. and nom. superfl.
Mixed forests; 2300-3700 m. W Sichuan, E and S Xizang, NW Yunnan [Bhutan, NE India, NE Myanmar, Nepal].