This genus is sometimes segregated into a separate family, Buddlejaceae; placed in Loganiaceae in Michigan Flora.
All species found in Buddleja
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. April 19, 2019. https://michiganflora.net/genus.aspx?id=Buddleja.