%0 Journal Article
%T THE ORIGIN AND DISTRIBUTION ON GENUS HEDYOTIS L.<br>耳草属(HedyotisL.)的起源及地理分布
%A WANG Rui-jiang
%A ZHAO Nan-xian
%A <br>王瑞江
%A 赵南先
%J 热带亚热带植物学报
%D 2001
%I 
%X As oneof thelargestandpantropicalgenerain thefamilyRubiaceae,thegenusHedyotis L.sensulato,includingsubgeneraHedyotis,Oldenlandia andHoustonia,is appliedin thispaper.They characterizedbyhavingtetramerousflowerswithvalvatecorollasandequalcalyxlobes,expanded,fleshy,peltateplacentaeand moderatelyflattenedcapsularwithsclerifiedendocarps.Basingon the extant literatures,699speciesareincludedinthisgenus.TropicalAfricaandAsiaaretwomoderndistribution centers.Endemicspeciesaredistributedinalltropicalcontinents.About68species(includingvarieties)growingin S.and SW China.The moderndistributionpatternand cytogeographydatarevealthat:(1)Hedyotis was originatedin theGondwanalandbeforelateJurassic,andmightbe originatedon the ampleareaof NEGondwanalandduringJurassic,eveninearlyTriassic;(2)Theydispersedinfourways fromtheoriginalcenter:eastward,to SE AsiaviaTurkey,IranandS.China,wherewasthesouthern areasof theLaurasialand;southeastward,to IndiaandAustraliaviapaleo-antarcticland;northward,to NorthAmericaviacentralpaleo-pacific;southwestward,to S.America,whichwasunitedwithAfricaat thattimeandwasalsoonemainpartof theGondwanaland.Thecontinentaldrift,especiallythebreakup of Gondwana,sloweddownthespeedof suchdispersalin Jurassictime.Subsequently,thespecies developedin theseseparatedcontinents.The globalglacierhadalsoplayedan importantrolein the presentdistributionpattern.
%K Hedyotis
%K Biogeography
%K Rubiaceae<br>耳草属
%K 地理分布
%K 茜草科
%K 起源
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=A74F042DF90151A4E3EF193E13FD5E1E&aid=684CB446AA9AA3F5&yid=14E7EF987E4155E6&vid=9CF7A0430CBB2DFD&iid=38B194292C032A66&sid=D5C73DEF4CF8FAF3&eid=CA5852BD1A173B3A&journal_id=1005-3395&journal_name=热带亚热带植物学报&referenced_num=4&reference_num=37