Description from Flora of China
Trees, 8-10 m tall. Bark gray-brown. Branchlets slender; young branchlets light purple, pubescent; old branches light brown, glabrous; winter buds conical, scales ciliate along margin. Leaves deciduous; petiole 6-10 cm, pubescent; leaf blade abaxially greenish, adaxially dark green, 4-9.5 × 4-11 cm, papery, abaxially tomentose or pilose, adaxially glabrous, primary veins 3, secondary veins 9-11 pairs, distinct adaxially, base rounded or rarely subcordate, 3-lobed, rarely 5-lobed; lobes ovate, margin undulate or with 1 or 2 obtuse teeth, apex acute; lateral lobes spreading horizontally. Inflorescence racemose, 3-5 cm, slender, pilose. Sepals 5, light greenish, oblong, ca. 5 mm. Petals 5, yellowish green, ca. 7 mm. Stamens 8. Ovary hairy. Fruit yellowish; pedicel slender. Nutlets irregularly convex, hispid; wing including nutlet 4-4.5 × 1-1.2 cm, wings spreading erectly or acutely. Fl. Apr, fr. Aug-Sep.
This species is very similar to Acer sterculiaceum subsp. franchetii but differs by its light brown branches, thinner 3-lobed leaves, lateral lobes spreading horizontally, inflorescence smaller and shorter, pedicels slender, and petioles and leaves abaxially pubescent.
● Sparse forests; 1200-1500 m. SE Gansu, SW Henan, Shaanxi.