Taxonomic Study Of Carex (Cyperaceae) In Daba Mountain Nature Reserve In Chongqing

Carex(Cyperaceae),with an estimated 2000 species and more than 500 species in China,is one of the most notorious genus for plant taxonomists.Having a better understanding of the phylogenetic and distribution patterns of this genus is of great significance to the classification of the whole vascular plants.The Daba Mountain Nature Reserve in Chengkou County of Chongqing Municipality is one of the most important nature reserves in China,where quite a few nomenclatural type specimens of Carex were collected.However,there is still no complete information on the classification of the genus so far.During this study,several field investigations were conducted in the reserve and more than 400 gatherings were collected.Based on comparative morphological studies on these specimens,a total of 30 species and three varieties were identified,which included nine new records to Chongqing,and five species and one variety newly registered in Chengkou County.The nine new records in Chongqing are C.meihsienica K.T.Fu,C.siderosticta Hance,C.retrofracta Kük.,C.erythrobasis H.Lév.& Vaniot,C.lancifolia C.B.Clarke,C.foraminata C.B.Clarke,C.bostrychostigma Maxim.,C.teinogyna Boott and C chungii Z.P.Wang.,and the five species and one variety newly registered in Chengkou County are C.simulans C.B.Clarke,C.heudesii H.Lév.&Vaniot,C.henryi(C.B.Clarke)T.Koyama,C.stipitinux Franch.,C grandiligulata Kük.and C.rubrobrunnea var taliensis(Franch.)Kük.The morphological structure and habitat characteristics of these new records were carefully studied,with photos of the habitats,inflorescence,basal spikes and bracts,upper spikes and bracts,nutlets,female glume and other anatomical structure presented.Morphological distinctiveness of the nine species and their diagnostic characters to their respectively affined species were given,and their known geographical distributions were also discussed.To date,the Dabashan Nature Reserve is found to be the morst northern margin of the known distribution of C.retrofracta Kük.,the morst southern margin of C.erythrobasis H.Lév.& Vaniot.Furthermore,concerning the elevations,C.foraminata C.B.Clarke and C.retrofracta Kük.were found with thehighest distribution in Daba Mountain Reserve,while C.erythrobasis H.Lév.& Vaniot with the lowest distribution.Together with other relevant references,a total of 46 species,two subspecies and four varieteis of Carex have been recorded in the Daba Mountain Reserves.A checklist was made with specimen or reference cited and key to those taxa were given for facilitate their identification.