XVI International Botanical Congess

This paper summarized the different views of former authors about the origin and development of the northwestern Chinese desert flora. In view of origin, according to the references from geohistory, palaeoclimate, palaeplant and palaeosporopollen, at the same time in combination with the types of plant distribution areas of modern florae and biological characteristic of typical groups in florae, the composition of the northwestern Chinese desert flora is divided into Tethys element and Cathaysian elements. The composition, origin and evolution of the two main elements are analysed detailedly and systematically. The views are put forward that Tethys element in flora is native, namely from the bank of Tethys or its traces, that Cathaysian element originates from Cathaysian continent, and that many areas in northwestern China are the component part of Cathaysian continent. All the views are incompletely different from former authors.Pan Xiao Ling