Description from Flora of China
Acer maximowiczianum Miquel, nom. illeg. superfl.; A. maximowiczianum subsp. megalocarpum (Rehder) A. E. Murray; A. nikoense var. megalocarpum Rehder; Negundo nikoense Miquel.
Trees to 20 m tall, androdioecious, sometimes andromonoecious. Bark gray. Branchlets slender; winter buds conical, scales 5 pairs, pubescent. Leaves deciduous; petiole 3-5 cm, densely pubescent; leaf blade subleathery, abaxially pale green and pilose, densely so on veins, midvein sparsely pubescent adaxially, lateral veins 12-14 pairs usually impressed adaxially, with 3 leaflets per petiole; leaflet blades oblong-elliptic or oblong-lanceolate, 7-14 × 3-6 cm, margin entire or remotely and shallowly serrate with obtuse teeth, apex acute or rarely acuminate. Inflorescence cymose, 3-5-flowered. Pedicel densely pilose. Pistillate flowers: sepals 5, obovate; petals 5, oblong-obovate; stamens 8, glabrous; disk glabrous, extrastaminal; ovary densely pubescent; style glabrous; stigmas widely spreading. Fruit yellowish brown; nutlets flat; wing including nutlet 3.5-4(-6) × ca. 1.2 cm, curved inward and wings spreading at 90°. Fl. Apr, fr. Sep.
Delendick (Brittonia 32: 286-290. 1980) reviewed the nomenclatural history and determined that Acer nikoense Maximowicz (13 Nov 1867) is the correct name for this taxon, not based on Negundo nikoense Miquel, and that the nomenclaturally superfluous synonym A. maximowiczianum Miquel (Dec 1867) is based on A. nikoense.
Mixed forests; 1000-1800 m. S Anhui, W Hubei, Hunan, N Jiangxi, E Sichuan, NW Zhejiang [Japan].