Volume 13 > Part 3 > Year 2017 > Page 549 > Sapindaceae > Acer

2. Acer chiangdaoense Santisukwfo-0000514114

Nord. J. Bot. 12: 696. 1992; Santisuk, Nat. Hist. Bull. Siam Soc. 46: 96. 1998. Fig. 2; Plate XL: 1.

Accepted Name : This is currently accepted.

Description : Stunted, low branched evergreen tree, 5–12 m tall; young branches puberulous to glabrescent. Leaves ovate, broadly ovate to somewhat triangular, 4–11 by 3–5 cm, apex acuminate to caudate, base cordate to almost truncate, margin entire, subcoriaceous, glabrous, glossy green above, silvery glaucous or grayish brown beneath, more or less hairy when young then puberulous (at least on main nerves), 3–5-nerved; petioles 1.6–5.2 cm long, puberulous when young, later glabrous. Inflorescence a corymb borne on leafy shoots, 3.4–8 cm long, puberulous. Flowers numerous. Infructescence puberulous to glabrescent. Fruits erect; 2–2.5 cm long including wings; mericarp angular tetrahedral, 5–7 mm long, angle between wings 90 degrees or less; locules glabrous, smooth and glossy inside.

Thailand : NORTHERN: Chiang Mai (type: Santisuk 2694, holotype -BKF), Chiang Rai (Doi Tung).

Distribution : Endemic to N Thailand.

Ecology : Scattered on the limestone, ca 1,780–2,150 m alt. Hitherto only known from the type locality on Doi Chiang Dao, Chiang Mai. Recent botanical excursions have also recorded its existence on the limestone ridged top of Doi Tung in Chiang Rai.

Vernacular : Kuam chiang dao (ก่วมเชียงดาว)(Chiang Mai).

Conservation Status: Unknown. An endemic restricted to limestone, possibly of high concern.