The Spreads of Mikania micrantha in China

Abstract

Mikania micrantha is of the new world origin and is widely naturalized in the old world tropics.It is the only one species of the Mikania genus of the new world that is sympatris with M\^cordata in the old world.This plant readily takes to distrurbed areas and tends to be “weedly,because M.micrantha grows very fast and is hard to control,it has become one of the worlds worst weeds.Its spread appears to have been facilitated by the increased activity in that part of World during World War Ⅱ.The earliest record of this plant in the old world is 1884 in Hong Kong,China,not is 1907 in Fiji.Its spread source in China is Hongkong zoological and Botanical Garden,where introduced this plant from the tropics of New world and cultivated for ornamental plant,and is widely naturalized in Hong Kong from 1919.The earliest record of this plant in Guangdong is 1984 in Shenzhen,at the late of 1980s and the earily of 1990s this plant invaded the coastline of Guangdong,and very widespread in Hongkong and Guangdong,China.Observably,its spread in China is related to global change.