Coefficient of Conservatism:
Coefficient of Wetness:
A. A. Reznicek
First collected in Michigan in 1941 by C. R. & F. N. Hanes along a roadside west of Schoolcraft in Kalamazoo Co. A population near Ann Arbor (Washtenaw Co.) was studied by Wagner et al. (1980), who found sterile hybrids with V. thapsus (V. ×kerneri Fritsch) to be rather common.
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 16, 2017. http://www.michiganflora.net/species.aspx?id=2681.