Abstract: Acer tienchuanense Fang et soong in Acta phytotax．Sin．11（2）：187-188(1966)quoad specimen K.H.Yang 54576．Species flores 6-numero, in Acer L. adhuc minus cognita. Arbor, 5-12 m alta. Cortcx flavescenti-cinereus. Ramuli robusti, glabri, hornotini flavescenti-cinerei, sparse lenticellis. Gemmae ellipsoideae, major, pe- rulae 4-6, ovatae, brunneae, superimpositae margine ciliolatis. Folia trifolio- lata; foliola chartacea, oblongo-lanceolata vel oblongo-elliptica, (9-) 10-14 cm longa, 2.5-5 cm lata, apice acuminata, basi truncatus, margine sparse crenata, supra viridia, glabra, subtus glauca, cinerea, ad nervos albo-villosa, ad axilles barbata; costa supra conspicua, subtus elevata; nervis lateralibus 6-7, subtus elevatis, petioluli foliolorum centralium 5-10 mm longi, petiolus 3.5-7 cm longus, glabrus, basi dilatatus. Inflorescentia corymbosa, 2.5-3.5 cm longa, glabra.

Key words: ne species, acer, emeishan