Seed dormancy and germination characteristics of Gaura parviflora, an exotic weed species in China Phenotypic variation and covariation in natural populations of the exotic weed Gaura parviflora in different habitat COMPARISON OF BASIC PHOTOSYNTHETIC CHARACTERISTICS BETWEEN EXOTIC INVADER WEED MIKANLA MICRANTHA AND ITS COMPANION SPECIES Influences of Population Density of Plantago virginica on Its Morphological Characters of Underground and Aboveground Organs Seed Production Characteristics of an Exotic Weed Mikania micrantha Classical biological control of exotic weeds Chemical mechanism of exotic weed invasion Quantitative survey on spring exotic weeds and the niche characteristics of dominant species in Nanjing The species and habitat characteristics of exotic weeds in Hangzhou Niche characteristic of exotic weeds in suburb and the impacts on biodiversity