Research On Vascular Bundle Flora Of Chongqing Municipal

Chongqing is situated at28°10′—32°12′N,latitude,105°17′—110°12′E.longitude.The total area is about 82400Km~2.The fern flora is very adundant and there are 604 species(including varieties)represent 120 genera and 47 families in Chongqing.The types of distribution are various and the distribution pattems are classified into 13 types.At the same time,the fern flora is arohaic,relic and pristine; Endemism is notable,the endemic species to China and Chongqing are 48 and 33;The fern has close affinity with tropical flora.Chongqing is rich in flora and there is found to have 4764 species including varieties of 1113 genera in 177 families of wild seed plants.It is makes up 49.17%of 360 families and 35.22%of 3160 genera and 15.18%of 31000 species in China.According to the comparative analysis of seed plants in Chongqing,15 areal-typus and 23 subtypus of genera and 11 areal-typus and 13 subtypus of family can be recognized.The amount of tropical genera is 446,being 40.07%of the total;and the temperate genera is 364,being 32.70%; and the east asia genera is 152,being 13.66%;and the cosmopolitan genera is 78,being 7.01%; the endemic genera to China is 73,being 6.56%.In all the 177 families of seed plants in Chongqing,it is makes up 49 cosmopolitan families and 51 tropical families and 29 temperate families,all occupying 72.88%of the total.And in all the seed plants there is 11 families including more than 101 species,13 families of 51-100 species,30 families of 21-50 species,95 families of 2-20 species and 28 families of only one species.The opinions are verified true that the "East Sichuan and Western Hubei" is one of the three endemic centers of Chinense flora and Chongqing is one of natural diffemtiation and modem distribution centers in China also.