| Senecio eximius Hemsl., 1881 |
| Senecio farfarus Hemsl., 1881 |
| Senecio filaris McVaugh, 1972 |
| Senecio filicifolius Greenm. ex Rose & Standl., 1914 |
| Senecio filifolius Nutt., 1841 |
| Senecio flaccidus Less., 1830 |
| Senecio flaccidus var. douglasii (DC.) B.L. Turner & T.M. Barkley, 1990 |
| Senecio flaccidus var. durangensis (Greenm.) T.M. Barkley, 1989 |
| Senecio flaccidus var. flaccidus Less., 1830 |
| Senecio flaccidus var. monoensis (Greene) B.L. Turner & T.M. Barkley, 1990 |
| Senecio floresiorum B.L. Turner, 1993 |
| Senecio galeottii Hemsl., 1881 |
| Senecio galicianus McVaugh, 1972 |
| Senecio galicianus var. manantlanensis R.R. Kowal, 1991 |
| Senecio gentryi (H. Rob. & Brettell) B.L. Turner & T.M. Barkley, 1989 |
| Senecio gerberifolius Sch. Bip. ex Hemsl., 1881 |
| Senecio gesneriifolius B.L. Turner, 1987 |
| Senecio ghiesbreghtii Regel, 1860 |
| Senecio ghiesbreghtii var. pauciflorus J.M. Coult., 1891 |
| Senecio ghiesbreghtii var. uspantanensis J.M. Coult., 1895 |