3. Acer amplum Rehder in Sargent, Pl. Wilson. 1: 86. 1911.
阔叶枫 kuo ye feng
Trees to 25 m tall, andromonoecious. Bark brownish, dark brown, or dark gray, smooth. Branchlets slender, glabrous; those of present year green or purplish green, those more than 2 years old gray or dark gray, lenticels rounded; winter buds purplish brown, subglobose or ovoid, glabrescent, scales 5 or 6 pairs. Leaves deciduous; petiole 4-14 cm, slender, glabrous or slightly puberulent near apex when young; leaf blade 7-26 × 5-25 cm, papery, abaxially light green, adaxially dark green or yellowish green, base rounded, subcordate, or truncate, 3- or 5-lobed or unlobed and entire, apex obtuse to caudate. Inflorescence terminal, corymbose, sessile or with peduncles ca. 5 mm, or up to 3 cm, numerous flowered, glabrous. Pedicel 1-2 mm, glabrous. Sepals 5, oblong-ovate and emarginate near apex, 4.5-5 mm, glabrous, apex obtuse. Petals 5, slightly longer than sepals. Stamens 8, ca. 5 mm in staminate flowers, shorter in pistillate, glabrous. Disk amphistaminal, slightly lobed and glabrous. Ovary glabrous, style glabrous, and stigmas recurved. Nutlets compressed, flat; wing including nutlet 2.5-5.5 × 0.6-1.5 cm, wings spreading at obtuse, acute, or erect angle. Fl. Apr, fr. Sep.
Forests, usually in valleys; 500-2500 m. S Anhui, Fujian, NW Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Yunnan, Zhejiang [Vietnam].