It is taxonomically complex, and many have proposed, or expect future proposals, to break it into species, subspecies, varieties, forms, and races. However, no such classification to date has received wide acceptance. It flowers as early as April in the southern part of its range, and as late as August in the northern part of its range.
- "40. Packera paupercula". Flora of North America 20: Page 570, 573, 579, 589, 595, 596. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242416912. Retrieved 2008-05-22.
- Alan S. Weakley (April 2008). "Flora of the Carolinas, Virginia, and Georgia, and Surrounding Areas". http://www.herbarium.unc.edu/flora.htm.