Arnica is a boreal, arctic, and alpine genus, in North America confined to the far north and higher elevations of the west. Our two species are restricted to the Lake Superior region and are rare and local (though A. cordifolia may locally form extensive vegetative colonies.
1. Lower leaves cordate.
A. cordifolia
1. Lower leaves lanceolate to narrowly ovate.
A. lonchophylla
All species found in Arnica
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. May 8, 2021. https://michiganflora.net/genus.aspx?id=Arnica.