Frangula

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

Frangula alnusGLOSSY BUCKTHORN 
Frangula purshianaCASCARA BUCKTHORN 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. July 20, 2017. http://michiganflora.net/genus.aspx?id=Frangula.