Plantago virginica L.,a weed originating from North America,was introduced into China about 1980's.Its characteristics research of biology and ecology in this paper shows:1.P.virginica L.has been widely distributed in east China; 2. its population is a transient one in Jinhua area,Zhejiang province;3.it has two types of flowers:anemophilous flower and cleistogamo us flower,and the later is the main one. climate condition,Plantago virginica L.population density and man-made interference have influences on th...