1. Teeth of leaves with prolonged spiny tips; phyllaries lacking resinous dots.
1. Teeth of leaves merely acute; phyllaries strongly resinous dotted.
All species found in Grindelia
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 11, 2017. http://www.michiganflora.net/genus.aspx?id=Grindelia.