83. Acer pinnatinervium Merrill, Brittonia. 4: 109. 1941.
楠叶枫 nan ye feng
Acer jingdongense T. Z. Hsu; A. machilifolium Hu & Cheng.
Trees, to 10 m tall, androdioecious. Bark gray-brown or dark brown, rough; branchlets slender, glabrous, those of present year purple-green or green, older ones gray-green or yellow-green. Winter buds purplish green, ovoid. Leaves persistent; petiole purple-green, 2-3.5 cm, glabrous; leaf blade abaxially gray-white, adaxially dark green and lucid, oblong-elliptic or elliptic, 10-14 × 3-6 cm, papery or subleathery, glabrous, pinnatinerved, lateral veins 8-12 pairs, base obtuse, apex caudate-acuminate, acumen 2-2.4 cm. Inflorescences cymose-paniculate, ca. 1.5 cm, pubescent. Sepals 5, yellowish green, ca. 2 × 7 mm. Petals 5, light yellow, ca. 1.8 × 0.4 mm. Stamens 8. Disk extrastaminal. Ovary purplish, villous. Fruit yellowish brown; nutlets flat, 1-2 cm × 6-7 mm; wing falcate, including nutlet 2-4 cm, wings spreading acutely. Fruit peduncle 1-2 cm, very slender. Fl. Aug-Oct, fr. Dec-Feb.
Mixed forests, scattered; 500-2400 m. SW Xizang, Yunnan [N India, Thailand].
This species is very rare and endangered.