| Begonia is one of the most valuable species for horticultural development in the 21 st century because of its wide variety of species,diverse morphology,rich variety,flowering and foliage appreciation,and wide range of applications.There are about 2100 species of this genus worldwide,mainly distributed in tropical and subtropical regions of Central America,South America,sub-Saharan Africa,East Asia,Southeast Asia and the Pacific islands(except Polynesia).A total of 281 species(including infraspecific taxonomic units)have been recorded in China.Southwest China and Guangxi are one of the centers of species diversity distribution of this genus.With a warm and humid climate and a typical karst landscape,Guizhou Province is rich in Begonia plant resources and is one of the main areas of concentrated distribution of Begonia plants in China.In this study,we synthesized information from the literature and conducted a taxonomic study of Begonia in Guizhou Province,based on field surveys and extensive specimen studies in Guizhou Province and surrounding provincial areas.The main contents included publication of new recorded species,formulation of new taxa,description of species,taxonomic discussion,formulation of Chinese names,clarification of reasons for misrepresented species,and preparation of species search lists.In addition,the species diversity and geographic distribution patterns were studied based on the updated list and geographic distribution database of wild Begonia in Guizhou Province.The main research results are as follows:(1)31 wild Begonia species(including subtaxa)were identified in Guizhou Province,including 26 endemic species in China and 8 endemic species in Guizhou,among which 6new recorded species were discovered and described B.dielsiana E.Pritz.ex Diels、B.qingchengshanensis Hong.Z.Li,C.I Peng&C.W.Lin、B.hymenocarpa C.Y.Wu、B.jingxiensis D.Fang&Y.G.Wei、B.pseudoedulis D.K.Tian,X.X.Feng&R.K.Li and B.fimbristipula Hance.After careful review of type specimens and original literature,three new taxa were proposed B.fanjingensis X.X.Bai&X.C.Li sp.nov.;B.jinyunensis C.-I Peng,B.Ding&Q.Wang var.renhuaiensis X.X.Bai&X.C.Li var.nov.and B.×wangmoensis X.X.Bai&X.C.Li sp.nov.A new Chinese name of B.cavaleriei as“西南秋海棠”were proposed;The cause of misloading B.rex Putz.,B.limprichtii Irmsch.,B.laminariae Irmsch.,B.modestiflora Kurz.,B.augustinei Hemsl.,B.algaia L.B.Sm.&Wassh.B.summoglabra Yu.were clarified.(2)In terms of horizontal distribution,wild begonias are distributed in all cities and states of Guizhou Province,with the highest species richness in Qianxinan Prefecture,with 17 species,accounting for 54.84% of the total in Guizhou Province.The distribution range of endemic species in Guizhou is relatively narrow,mainly in northern and southwestern Guizhou,while areas with high endemic rates are mainly concentrated in northern Guizhou.Duyun City,Libo and County counties are the areas with the richest species diversity of begonias,and the 14 hotspot counties selected in this study represented a total of 100% of begonias.By calculating and comparing the similarity coefficients,it was found that the highest degree of similarity between begonias was found in Qianxinan and Qiannan states,indicating a high degree of similarity in the differences in species composition and composition of endemic components between these two regions among the nine cities and states.(3)In terms of vertical distribution,the vertical distribution of begonias in Guizhou Province is remarkable,with a large altitude span from 227 m to 2900 m above sea level,mainly in the range of 147–1500 m,with a total of 31 species.A total of 31 species,including all species of wild begonias in Guizhou,indicate that this altitude range is most suitable for the growth of begonias.According to the morphological type of stems,14 of the 31 species of begonias in Guizhou are rhizomes,7 are erect stem and 10 are bulbous.The majority of rhizomatous begonias grow at altitudes below 1500 m.The overall number of species of erect stemmed begonias is relatively small,but there are species growing at all altitudes,indicating a wider range of adaptation.Begonias with bulbous roots are relatively less distributed at low altitudes of 147–500 m,and then gradually increase in altitude,reaching a peak at 1000–1500m elevation. |
