1. Disk cylindrical, longer than the rays; rays less than 2 (-2.5) cm long; pappus of 1-2 tiny teeth.
1. Disk hemispherical (or even nearly spherical) to short-cylindrical, much shorter than the rays; rays ca. 2.5-3.5 (-4.5) cm long; pappus absent.
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. March 16, 2025
https://mifloradev.lsa.umich.edu/flora-demo/#/genus/Ratibida