| Erigeron reconditus Nesom, 2021 |
| Erigeron reinanus G.L. Nesom, 2000 |
| Erigeron rhizomactis G.L. Nesom, 1989 |
| Erigeron saracachiensis Nesom, 2021 |
| Erigeron scaberrimus Gardner, 1884 |
| Erigeron scaposus DC., 1836 |
| Erigeron sceptrifer G.L. Nesom, 1990 |
| Erigeron schiedeanus Less., 1830 |
| Erigeron scoparioides G.L. Nesom, 1989 |
| Erigeron seemannii (Sch. Bip.) Greene, 1891 |
| Erigeron socorrensis Brandegee, 1899 |
| Erigeron sordidus Gillies ex Hook. & Arn., 1837 |
| Erigeron spathulatus Vahl, 1793 |
| Erigeron speciosus (Lindl.) DC., 1836 |
| Erigeron stanfordii I.M. Johnst. ex G.L. Nesom, 1981 |
| Erigeron strigulosus Greene, 1891 |
| Erigeron subacaulis (McVaugh) G.L. Nesom, 1982 |
| Erigeron tenellus DC., 1836 |
| Erigeron tephropodus G.L. Nesom, 1981 |
| Erigeron tracyi Greene, 1902 |