1. Basal leaves at least twice-compound; margins of leaflets minutely ciliate, with ca. 3โ5 (โ7) coarse and irregular teeth or lobes on a side.
T. chapmanii
1. Basal leaves simple or trifoliolate; margins of leaflets smooth and glabrous, the principal ones with ca. 10โ40 fine and regular teeth on a side.
T. trifoliatum
All species found in Thaspium
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. January 25, 2021. https://michiganflora.net/genus.aspx?id=Thaspium.