乌头荠族的地理分布与系统

乌头荠族植物的地理分布表明，其基本上是１个北温带的族，该族植物有１４属，８个分布区类型，亚洲的中部及西北部一带，特别是伊朗－吐兰区的西北部，是其原始分布与分化的中心；欧洲中部；西北部及巴尔干半岛并散布到和北美洲的西北部是其次生的分布与分化中心。根据该族原始类群和生境的分布分析，推测以上地区有可能是这类植物的发源地。首次从环境气体的变化和该族形态特征演化探讨了现代分布格局的形成原因。

THE GEOGRAPHICAL DISTRIBUTION AND THE SYSTEM OF EUCLIDIEAE(CRUCIFERAE)

The geographical distribution,the center of distribution and differentiation ofEuclidieae,its system and evolutionary trends are discussed in this paper. (1)The systematic positions:There are 14 genera,about 21 species in the Tribe are recog-nized.A typial Tribe Euclidieae in the north temperate zone on the floristic analysis- (2)The floristic analysis ofspecies and genera in the Tribe shows that the region,the richestboth in genera and species,and endemic species and genera,as Takhtajan's work pointed out,there are 8 distribution types(including China)in the Tribe Euclidieae,Center and North-West-ern in Asia,and the Old World(see Table 1,2),especially in Center and North-Western Asia,areendemic elements five genera and 8 species of this Tribe occur in the Center and North-WesternAsia,especially in the region from the Irano-Turanian 13 genera,20 species. (3)The primarv center of the distribution and differentiation of this Tribe is center andNorth-Western Asia, especially in the region from the Iran to Turkey,since 14 genera and 21species are found in Center and North-Western,and North-Eastern Asia,including the mostprimitive genus Tauscheria, probably occur in the region. The secondary center of distributionand differentiation is Center and North-Western and Balkan Pen in Europe,North-WesternAnica andNofth-Westem Amcrican