The rare and endangered plants of seed plant flora at Qinling Mt.

There are 34 species of national key preserving plants in seed plant flora of Qinling Mt. These plants are divided into three types ,such as 2 endangered species, 17 rare species and 15 vulnerable species. The geographical compositions of the rare and endangered plants are studied. The result shows that the north temperate element, China endemic element and East Asia element are the major geographical compositions at genus level. The geographical compositions of species takes Central China as the dominant element. The result of the field investigation shows that 2 species distribute in the north slope, 7 species in the south slope, and other 25 species at Qinling Mt. widely. The vertical distribution of these species is mostly in range of the elevation 1 000-2 000 m.