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. July 17, 2018. https://michiganflora.net/genus.aspx?id=Buddleja.