| Scolospermum Less., 1830 |
| Scolospermum baltimoroides Less., 1830 |
| Seala Adans., 1763 |
| Selloa Kunth, 1818 |
| Selloa glutinosa Spreng., 1819 |
| Selloa macdonaldii (B.L. Turner) H. Rob., 1997 |
| Selloa nudata Nutt., 1822 |
| Selloa plantaginea Kunth, 1818 |
| Senecio L., 1753 |
| Senecio acerifolius Sessé & Moc., 1894 |
| Senecio actinella Greene, 1883 |
| Senecio acutangulus (Bertol.) Hemsl., 1881 |
| Senecio alatipes Greenm., 1914 |
| Senecio albo-lutescens Sch. Bip., 1845 |
| Senecio albonervius Greenm., 1914 |
| Senecio alienus B.L. Rob. & Seaton, 1893 |
| Senecio alvarezensis Greenm., 1912 |
| Senecio ammophilus Greene, 1885 |
| Senecio amplifolius (DC.) Sch. Bip., 1845 |
| Senecio amplus J. Rémy, 1849 |