Recognition of Frangula follows Bolmgren & Oxelman (2004).
1. Pedicels of flowers (and fruiting peduncles) glabrous or nearly so; leaf blades 2.5–8 cm long.
F. alnus
1. Pedicels of flowers and fruiting peduncles pubescent; leaf blades ca. 8–12 cm long.
F. purshiana
All species found in Frangula
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. May 29, 2022. https://michiganflora.net/genus.aspx?id=Frangula.