| Bidens oaxacana Melchert, 1990 |
| Bidens ocellatus (Greenm.) Melchert, 1991 |
| Bidens odorata Cav., 1791 |
| Bidens odorata var. chilpancingensis R.E. Ballard, 1986 |
| Bidens odorata var. oaxacencis R.E. Ballard, 1986 |
| Bidens odorata var. odorata Cav., 1791 |
| Bidens odorata var. rosea (Sch. Bip.) Melchert, 1990 |
| Bidens oligantha Brandegee, 1905 |
| Bidens oligocarpa Sherff, 1931 |
| Bidens ostruthioides (DC.) Sch. Bip., 1856 |
| Bidens ostruthioides var. ostruthioides (DC.) Sch. Bip., 1856 |
| Bidens pilosa L., 1753 |
| Bidens pilosa f. radiata Sch. Bip., 1844 |
| Bidens pilosa var. minor (Blume) Sherff, 1925 |
| Bidens pilosa var. pilosa L., 1753 |
| Bidens pilosa var. radiata (Sch. Bip.) J.A. Schmidt, 1852 |
| Bidens polyglossa Sherff, 1964 |
| Bidens pringlei Greenm., 1905 |
| Bidens pseudalausensis Sherff, 1917 |
| Bidens pueblensis (Sherff) Melchert, 1990 |