Calyptocarpus,a Newly Naturalized Genus of Asteraceae in Guangdong
This paper reported a newly naturalized genus of Asteraceae,Calyptocarpus Less.in Guangdong.C.vialis Less.is native to the southern United States,Mexico and Cuba,and was previously reported to be naturalized in China(Taiwan,Yunnan and Guangxi),Indonesia(Java),Oceania,India and Africa.Many populations of this invasive species were discovered in Chebei Chong,Guangzhou.It grows vigorously and tends to take over the habitat of other native herbaceous plants,which seems to be an invasive species and should attract the attention of relevant departments.Calyptocarpus vialis is similar to Synedrella nodiflora(L.)Gaertn.,but markedly differs by having prostrate stems,homogeneous achenes with wingless ray ones,and palea with an acute apex.The vouchers are deposited in the herbarium of South China Botanical Garden,Chinese Academy of Sciences(IBSC).