The Biology of Canadian Weeds. 140. Hesperis matronalis L.

The cruciferous weed Hesperis matronalis, dame's rocket (Brassicaceae), is an introduced Eurasian garden plant that began to escape shortly after its introduction to North America in the 19th century. It has gradually become naturalized across Canada and the United States, and has become invasive. It is not a major weed of crops, but is widespread in natural and conservation areas, particularly in thickets, open woodlands, forest margins and along streambanks, in parts of eastern and southern Ontario and western Quebec in Canada, and in New England and the midwest in the United States. In these habitats it can crowd out native vegetation and subsequently reduce biodiversity. Serving as an alternate host to a number of viruses, the species has the potential to infect cruciferous vegetable crops and garden plants. Despite its invasive potential, it continues to be sold at garden centres in both Canada and the United States. Key words: Hesperis matronalis, dame's-rocket, julienne des dames, weed biology, invasive alien, HEVMA