Coefficient of Conservatism:
Coefficient of Wetness:
A northern species in eastern North America, isolated in Michigan on Passage Island and Gull Islands of Isle Royale National Park, where it grows in exposed rock crevices above Lake Superior.
Only on Isle Royale
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 18, 2017. http://michiganflora.net/species.aspx?id=644.