A Taxonomic Study On The Genus Acer In Henan Province

In this paper, the brief history and the current condition in the classification of the genus Acer Linn.have been reviewed.I have also compared the precision of the ancestors'studies and then studied the classificating evidence,the law of origin and evolution and geographical distribution.By identifying and studying the specimens ,1 ensure that there lie 20 species and subspecies and 8 varieties which belong to 3 subgenus in Henan province.I add 3 species and 2 varieties which were not recorded in Flora of Henan such as Acer tegnentosum Maxim. A.tsinglingense Fang et Hsieh , A.shensiense Fang , A.buergerianum Miq.var.ningpoense (Hance)Rehd. and A. Tetramerum Pax var.haopingense Fang.Some names have been revised in Flora of Henan as follows:A.griseum (Franch.) Pax has been treated as a synonym of A.shensiense Fang and A.oblongum Wall ex DC.var. trilobum Henry has been combined as A. oblongum Wall ex DC. What's more, I agree on the treatment of Flora of China where A.tetramerum Pax var. lobulatum Rehd.was treated as synonym of A.tetramerum Pax. Finnally,I make some explanation of the species and subspecies and varieties whose specimen were not seen but asked to be verified further.Moreover, a systematic arrangement on the genus in Henan province and artificial key to the species have been made. Characteristic description have been given to all the taxone and followed by the distribution and habitat. Some taxone have also been discussed briefly.