Coefficient of Conservatism:
Coefficient of Wetness:
A native of the Old World, rarely established in North America; first collected in Houghton Co. in 1936. Apparently slowly spreading along roadsides and ditches in Michigan.
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 17, 2017. http://michiganflora.net/species.aspx?id=1515.