A FLORISTIC STUDY ON SEED PLANTS IN NINGXIA

There are 1415 species (including infraspecific taxon) of the seed plants belonging to 101families and 493 genera (exclude cultivated plants) in Ningxia municpality. Among them, there are 11 species belonging to 11 genera and 3 families are of gymnosperm and 1404 species belonging to 486 genera and 98 families are of angiosperm. In addition, there are 12 Chinese endemic genera and 21 Ningxia endemic species. Based on the analysis of compositions and the geographical elements and characteristics of the flora, the paper has discussed the major characteristics of the flora as follows: Species are comparatively poor; the geographical elements of the flora are comparatively complex, and the genera of temperate are the dominant areal types, among them, north temperate play the part of an important role in the flora; the flora is ancient origin, but has also younger elements; the flora has widely relate to other area, and the flora is the crisscrossing and assembling of diversified geographical elements, or the crisscrossing and assembling, mixing and transition of North China, Neimenggu and Tanggute three floristic elements; the Ningxia endemic taxa and rare and endangered seed plants are comparatively low.