湖南通道侗族自治县种子植物属的区系研究

通道侗族自治县种子植物区系715属，归为14种区系成分，其中，泛热带分布（132属，占20％）、北温带分布（106属，占16．06％）、热带亚洲分布（100属，占15．15％）及东亚分布（87属，占13．18％）所占比例较大；热带地理成分349属，占总属数的52．88％，温带地理成分311属，占总属数的47．12％，与相邻植物区系的比较表明，通道植物区系与花坪和都庞岭的关系较为密切，而与三清山及八大公山的相似性程度稍低，在与之相比较的7个相邻植物区系中，除广西的花坪外，通道的R／T值最高，表明通道植物区系的热带性程度高于相近纬度的其他6个地区，该区植物区系总体上表现区系成分复杂多样，显示出明显的过渡性质，而在该县南部（传素—独坡一线以南）汇集有丰富的华南热带成分，显示出热带北缘性质。

Study on the Flora of Seed Plants in Tongdao Dongzu Self-government County of Hunan Province

There are 715 generas in Tongdao seed flora,and these generas can be grouped into 14 areal-types,among them,the four areal-types which accounting for larger proportion are Pantropic(132 generas,account for 20%),North temperate(106 generas,account for 16.06%),Trop.Asia(100 generas,account for 15.15%)and E.Asia(87generas,account for 13.18%);There are 349 generas belong to tropic character,account for 52.88% of the total generas,and 311 generas belong to temperate character,account for 47.12% of the total generas.The result of similarity comparing with neighbour floras indicate that there are tight relationship between Tongdao flora and Huapin flora,and Doupanglin flora,moreover,the similarity coefficient of genera between Tongdao and Shanqinshan and Badagongshan is lower a bit,among 7 floras compared with Tongdao flora,except Huapin flora,the R/T value of Tongdao flora genera is the highest,it indicate that the degree of tropic character in Tongdao flora is highest among other 6 floras.The floristic character of seed plants in Tongdao represented complexity and multiplicity on floristic ingredient as a whole,and showed obvious transition character,but there are abundance element of South China Flora on the south part(south of the line from Chuangshou to Doupo),so showed its tropic north edge character.