| Bidens schaffneri (A. Gray) Sherff, 1913 |
| Bidens schaffneri var. schaffneri (A. Gray) Sherff, 1913 |
| Bidens schaffneri var. wrightii (A. Gray) Melchert, 1990 |
| Bidens seemannii Sch. Bip., 1856 |
| Bidens serboana B.L. Turner, 2013 |
| Bidens serrulata (Poir.) Desf., 1829 |
| Bidens serrulata var. serrulata (Poir.) Desf., 1829 |
| Bidens serrulata var. sharpii Sherff, 1950 |
| Bidens sharpii (Sherff) Melchert, 1990 |
| Bidens sharpii var. sharpii (Sherff) Melchert, 1990 |
| Bidens sharpii var. tamazulapana Melchert, 1990 |
| Bidens socorrensis Moran & G.A. Levin, 1989 |
| Bidens squarrosa Kunth, 1818 |
| Bidens squarrosa var. atrostriata Roseman, 1990 |
| Bidens squarrosa var. speciosa Roseman, 1990 |
| Bidens squarrosa var. squarrosa Kunth, 1818 |
| Bidens squarrosa var. tereticaulis (DC.) Roseman, 1990 |
| Bidens subspiralis McVaugh, 1972 |
| Bidens tenuisecta A. Gray, 1849 |
| Bidens tereticaulis DC., 1836 |