云南蔷薇科植物的区系特征和地理分布

The Floristic Characteristics and Geographical Distribution of Rosaceae in Yunnan

蔷薇科是云南种子植物区系中的第５大科，有４１属４５６种，其属种分别占我国蔷薇科的７４．５％和５２．２％。云南蔷薇科植物的区系物征：１）云南蔷薇科属种十分丰富，分别占国产属的３／４和种的一半以上；而且该科植物中原始的、中间过渡的和进化的类群在云南均有分布。２）区系地理成份相当复杂，以包括北温带和东亚等分布类型为主的温带成分占优势。３）蔷薇科在云南的地理分布为５个区。该科植物在滇西、滇西北区种类最为丰富，占总种数的６５．７％，其次是中部高原区、滇东南区及滇南和滇西南区较少，滇东北区最少。云南是蔷薇科植物的一个现代分布中心和分化中心之一。

Rosaceae is one of the five largest of Yunnan flora, consisting of 41 genera and 456 species. The total species number is less than those of Compositae, Compositae, Graminae, Orchidaceae,and Papilionaceae in Yunnan. The percentage of genera and species numbers is 74.5% and 52.2% of the total number in the rosaceous flora in China respectively. The four subfamilies of Rosaceae including primitive, intermediate and advanced groups have been found in Yunnan. These groups consist of 9 types of floristic el- ements, i. e. l genera belongs to cosmopolitan, 2 genera belong to pantropic, 2 genera to Trop. Asian, 15 genera to North Temperate, 3 genera to E. Asian & N. Amer.disjunct, 5 genera to old world Tem- perate, 2 genera to Tem. Asian, 8 genera to E. Asian and 2 genera are Endemic to Chima. It is obvious that Rosaceae in Yunnan comprises holarctic, Ancient Mediterranean and paleotropical elements,in which the temperate components are the dominant. The chaeacteristice of the floristic composition of Rosaceae in Yunnan may be summarized as follows: 1) Yunnan in rich in both genera and species of the Rosaceae famil which are diverse in forms,including the primitive,intermediate and advanced groups;2)The geographi- cal elements are quite compels, mostly belonging to the temperate, in which the North Tempate, E Asia and the elements endemic to China are dominant;3)The geographical distribution of Rosaceae in Yunnan can be divided into 5 regions, i. e. southern and southwestern, southeastern, central-plateau,western and northwestern, northeastern. The rosaceous plants are very abundant in the western and northwestern ar- eas, next in central- plateau area,fewer in the southeastern,southern and areas and very rare in the northeastern area; 4)The rosaceous flora of Yunnan has close relationships with those in the neighbor regions,i. e. Sichuan, Guizhou, Xizang and Guangxi. Besides, it is connected with flora of northern India, Myanmar, Vietnam, and etc.