| Asteraceae | |
Silphium perfoliatum subsp. connatum
| (L.) Cruden | Castanea 27(2): 90 | 1962 |
| Asteraceae | |
Silphium perfoliatum var. connatum
| (L.) Cronquist | Brittonia 29(2): 223 | 1977 |
| Asteraceae | |
Silphium perfoliatum var. perfoliatum
| | | |
| Asteraceae | |
Silphium perfoliatum fo. petiolatum
| E.J. Palmer & Steyerm. | Brittonia 10(3): 119 | 1958 |