论无心菜属的地理分布.pdf

． ’ 类 学 报 。㈤ 。咄 m ActaPhyt0七日x0n鲫 icaSinica ， ． 论无心菜属的地理分布 几 (中国科学院西j 五i；西宁8lo∞1) 7十“‘，，。D7， … … ，… oN THE GEoGRAPHICAL DISTRIBUTIoN oF ARENA冠，A L． Zhou L—hua (NorthwestPtate~ InstituteofB kg ，Acod~daSinlca，Xining810001) Abstract Thepresentpaperaimstodiscussthegeographica1distributionoftheArenm~ L． onthebasisoftheunity ofphylogenyandprocessofdispersalin plants．Thereare 306 speciesofArenarm intheworld，belongingto10subgeneraand24sections．Arenm~ are mainlydistributedinEurasia，AmericaandnorthernAfrica．Accordnigtothegeographical elementsofArenm~ in theworld，eightgeographicaldistribution pattern na d11vraiants raedividde ．According toTakhtajansandWusviewpointsofphytochroai，thenumberof speciesiscountedforeachregion，whichshowsclearlythattheMediterranaen，W ．Asiato northwestC．AsiaregionandHengduna MountainstoQinghai：Xiaang(Tibet)Plataeure-