| Bidens purpurea DC., 1836 |
| Bidens purpusiorum Bitter & Petersen, 1921 |
| Bidens refracta Brandegee, 1890 |
| Bidens reptans (L.) G. Don, 1839 |
| Bidens reptans var. coreopsidis (DC.) Sherff, 1948 |
| Bidens reptans var. reptans (L.) G. Don, 1839 |
| Bidens reptans var. urbanii (Greenm.) O.E. Schulz, 1911 |
| Bidens riparia Kunth, 1818 |
| Bidens riparia var. refracta (Brandegee) O.E. Schulz, 1911 |
| Bidens riparia var. riparia Kunth, 1818 |
| Bidens rosea Sch. Bip., 1856 |
| Bidens rosea var. aequisquama Fernald, 1907 |
| Bidens rosemaniana B.L. Turner & Melchert, 2010 |
| Bidens rostrata Melchert, 1975 |
| Bidens saltillensis Melchert, 1990 |
| Bidens sambucifolia Cav., 1795 |
| Bidens sarmentosa Greenm., 1905 |
| Bidens scandens L., 1753 |
| Bidens schaffneri (A. Gray) Sherff, 1913 |
| Bidens schaffneri var. schaffneri (A. Gray) Sherff, 1913 |