9. Acer tenellum Pax, Hooker’s Icon. Pl. 19: t. 1897. 1889.
薄叶枫 bao ye feng
Trees usually ca. 7 m tall, andromonoecious. Bark gray or dark gray, smooth. Branchlets slender; lenticels rounded or ovate, small; winter buds small, scales ca. 4 pairs. Leaves deciduous; petiole 3-6 cm, slender, glabrous; leaf blade abaxially pale green, adaxially dark green, suborbicular or ovate, 4-6 × 3-6 cm, membranous, abaxially glabrous except slightly pubescent at vein axils, adaxially glabrous, veins raised abaxially, base subcordate or cordate, usually 3-lobed, rarely undivided; middle lobe obtuse, margin entire or slightly sinuate, apex acute or rarely acuminate; lateral lobes obtuse or triangular-ovate, margin entire, apex acute or obtuse. Inflorescence terminal, corymbose, glabrous. Pedicel ca. 2 cm. Sepals 5, oblong, 2-3 mm, both surfaces glabrous, margin slightly ciliate. Petals 5, yellowish green, oblong-obovate, 2-3 mm, glabrous. Stamens 8, in staminate flowers ca. as long as or slightly shorter than petals; filaments glabrous; anthers yellow. Disk amphistaminal, lobed, glabrous. Ovary glabrous, compressed; style glabrous, very short, connate at base; stigmas recurved. Fruit purple when young, glabrous; wing including nutlet 2-3 cm; nutlets compressed, with wings spreading nearly horizontally. Fl. May, fr. Sep.
● Mixed forests, valleys; 1200-1900 m. W Hubei, E and SE Sichuan.