1. Terminal inflorescence densely crowded, compact, the long bracts with prolonged spine-tipped teeth; calyx mostly 10 mm or more long.
1. Terminal inflorescence elongate after flowering, the small bracts scarcely if at all exceeding the pedicels, entire, spineless; calyx ca. 6-8 mm long.
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/Dracocephalum