1. Leaves undivided (though regularly toothed).
T. balsamita
1. Leaves pinnatifid or bipinnatifid.
2. Rays absent or yellow.
3. Heads (12–) 13–19 (–22) mm broad; leaves ± hairy.
T. bipinnatum
3. Heads 5–10 mm broad; leaves glabrous or nearly so.
T. vulgare
2. Rays present, white or pink.
4. Rays white, 4 – 8 mm long; heads numerous per stem (except in depauperate plants)
T. parthenium
4. Rays bright pink, fading to a dull pale pink, ca. 12 – 20 mm long; heads few (1-3) per stem
T. coccineum
All species found in Tanacetum
Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. March 1, 2021. https://michiganflora.net/genus.aspx?id=Tanacetum.