Description from Flora of China
Acer miaotaiense var. glabrum M. C. Wang; A. miyabei Maximowicz subsp. miaotaiense (P. C. Tsoong) A. E. Murray; A. yangjuechi W. P. Fang & P. L. Chiu.
Trees to 25 m tall. Bark brownish gray, rough. Branchlets glabrous; lenticels rounded; winter buds ellipsoid, scales 4. Leaves deciduous; petiole 6-7 cm, glabrous; leaf blade broadly ovate, (4-)7-9 × 5-8 cm, papery, abaxially pubescent, adaxially glabrous, primary veins 3-5, secondary veins 5-7 pairs, base cordate or subcordate, 3- or 5-lobed; lobes ovate, margin undulate, apex acute. Inflorescence terminal, corymbose-paniculate. Flowers yellow-green. Sepals 5, oblong, ca. 4 mm, margin ciliate. Petals 5, obovate-lanceolate, ca. as long as sepals. Stamens 8. Disk orbicular, margin 5-repand-lobed. Infructescence corymbose, glabrous; pedicel 3-6 mm; samara pubescent or rarely glabrous. Nutlets flat, ca. 8 mm in diam.; wing including nutlet 2-2.5 × 0.8-0.9 cm; wings spreading horizontally. Fl. May, fr. Sep.
This taxon is closely related to Acer miyabei Maximowicz; the bark, inflorescences, flowers, and fruit are very similar. For one of us (de Jong), A. miaotaiense is a subspecies of A. miyabei.
● Mixed forests; 700-1600 m. SE Gansu, SW Henan, NW Hubei, S Shaanxi, Zhejiang.