Grindelia squarrosa var. serrulata (Rydberg) Steyermark

Grindelia squarrosa var. serrulata (Rydberg) Steyermark is a synonym sensu FNA Ed. Comm., 2006b of:

Grindelia squarrosa (Pursh) Dunal var. squarrosa, an accepted variety name sensu Bartoli & Tortosa, 2012.