Acer calcaratum and A. acuminatum, two poorly known and very rare species, occurring in Southeast Asia and the Himalayas respectively, were discovered recently in Yunnan Province and Xizang (Tibet) Autonomous Region in China. Acer calcaratum belongs to sect. Palmata ser. Sinensia, and is characterized by its 3 basally-nerved and 3-lobed leaves, with a rounded base, short, corymbose inflorescence and with few fruits, usually with only one large, well-developed samara, the nutlet more or less

more »

... d. Acer acuminatum belongs to sect. Arguta, and is characterized by its 3-or 5-lobed leaf blade, the lateral lobes usually as long as central lobe, apex of the lateral lobes caudate-acuminate, and infructescence 12-20 cm long.