Description from Flora of China
Acer davidii Franchet f. trilobatum Diels; A. sikkimense Miquel subsp. metcalfii (Rehder) P. C. de Jong.
Trees to 10 m tall. Bark smooth. Branchlets slender. Leaves deciduous; petiole 2-3(-5) cm, glabrous; leaf blade adaxially dark green, 10-14 × 7-11 cm, subleathery, both surfaces glabrous, lateral veins 9-11 pairs, base subcordate or rounded, 3-lobed; middle and lateral lobes triangular-ovate, margin coarsely serrate with obtuse teeth, except for entire acumen, apex acuminate. Flowers unknown. Infructescence racemose, 15-flowered. Fruiting pedicel ca. 5 mm, slender, glabrous. Fruit 6-9, brownish yellow; nutlets ca. 8 × 6 mm; wing including nutlet 2.2-2.5 cm × ca. 8 mm, wings spreading obtusely. Fl. unknown, fr. Sep.
One of us (Chang) believes that this species would be better treated as a synonym of Acer grosseri (see note under A. davidii subsp. grosseri). However, one of us (Chen) disagrees because A. metcalfii is distributed only in S China, whereas A. grosseri is distributed further N in China.
● Mixed forests, streamsides; 800-1500 m. N Guangdong, NE Guangxi, SE Guizhou, S Hunan.