1. Basal leaves at least twice-compound; margins of leaflets minutely ciliate, with ca. 3-5 (-7) coarse and irregular teeth or lobes on a side.
1. Basal leaves simple or trifoliolate; margins of leaflets smooth and glabrous, the principal ones with ca. 10-40 fine and regular teeth on a side.
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. March 19, 2025
https://mifloradev.lsa.umich.edu/flora-demo/#/genus/Thaspium