| Asteraceae | |
Grindelia squarrosa fo. angustior
| Steyerm. | Ann. Missouri Bot. Gard. 21(3): 481–482 | 1934 |
| Asteraceae | |
Grindelia squarrosa fo. depressa
| Steyerm. | Ann. Missouri Bot. Gard. 21(3): 480 | 1934 |
| Asteraceae | |
Grindelia squarrosa var. eligulata
| (Steyerm.) Adr. Bartoli & Tortosa | Ann. Missouri Bot. Gard. 98(4): 499 | 2011 [2012] |
| Asteraceae | |
Grindelia squarrosa var. grandiflora
| (Hook.) A. Gray | Smithsonian Contr. Knowl. 3(5): 98 | 1852 |
| Asteraceae | |
Grindelia squarrosa var. hirtella
| B.L. Rob. & Greenm. | Amer. J. Sci. Arts, ser. 3 50(296): 153 | 1895 |
| Asteraceae | |
Grindelia squarrosa var. integrifolia
| (Nutt.) B. Boivin | Phytologia 23(1): 14 | 1972 |
| Asteraceae | |
Grindelia squarrosa var. nuda
| (Alph. Wood) A. Gray | Syn. Fl. N. Amer. 1(2): 118 | 1884 |
| Asteraceae | |
Grindelia squarrosa fo. pseudopinnatifida
| (D. Löve & C. Bernard) Adr. Bartoli & Tortosa | Ann. Missouri Bot. Gard. 98(4): 499 | 2011 [2012] |
| Asteraceae | |
Grindelia squarrosa var. quasiperennis
| Lunell | Amer. Midl. Naturalist 3(5–6): 143 | 1913 |
| Asteraceae | |
Grindelia squarrosa var. serrulata
| (Rydb.) Steyerm. | Ann. Missouri Bot. Gard. 21(1): 482 | 1934 |
| Asteraceae | |
Grindelia squarrosa fo. squarrosa
| | | |
| Asteraceae | |
Grindelia squarrosa var. squarrosa
| | | |