The Biology of Canadian Weeds. 153. Stachys palustris L.

Abstract

Darbyshire, S. J., Francis, A., Mulligan, G. A. and Graham, G. 2014. The Biology of Canadian Weeds. 153. Stachys palustris L. Can. J. Plant Sci. 94: 709–722. Marsh hedge-nettle, Stachys palustris, is a perennial Eurasian member of the mint family, which has become naturalized and weedy in some parts of eastern North America. It is a hexaploid member of a holarctic species complex, which differs morphologically from the primarily tetraploid North American forms. The production of fleshy tuberous rhizomes is the most significant distinctive feature. In Canada, it has been a weed of potato and root crops in Nova Scotia, New Brunswick and Prince Edward Island, although other crops and areas, such as soybean in Ontario, are also affected. Usually considered a wetland plant, it readily spreads into drier arable fields from adjacent ditches and wetlands. Several herbicides available for use in Canada have been found to provide limited long-term suppression in agricultural systems, with the best results obtained using combined pre-emergent and post-emergent applications.