TAXONOMIC STUDIES ON POPULUS L. IN SOUTHWESTERN CHINA (Ⅰ)

In this paper, the additional description of populus kangdingensis is presented, four nomenclatural new combinations ( i. e. P. kangdingensis var.lancifolia, P.kangdingensis var. schneideri, P.kangdingensis var. tibetica and P. pseudoglauca var. weixi )are made, sixteen scientific names in literature (i.e. P. adenopoda f. microcarpa, P. adenopoda var. platyphylla, P.bonatii, P.haoana, P.haoana var.megaphylla, P. haoana var.microcarpa,P.mainlingensis, P.purdomii var.rockii, P. qamdoensis, P.rotundifolia var.bonatii, P.schneideri, P. schneideri var. tibetica, P. yatungensis,P. yatungensis var. crenata,P. yatungensis var. trichorachis and P. yunnanensis var. pedicellata)are treated as new synonyms,two species (i.e.P.xiangchengensis and P. yuana)are considered to be natural hybrids, two species(i.e. P.purdomii and P.rotundifolia) are recorded respectively in Yunnan-Xizang region and Sichuan-Yunnan region for the first time and two varieties (i. e. P. lasiocarpa var. psiloclada and P. lasiocarpa var. yiliangensis )are described as new in this area.