| Dalea obovatifolia var. uncifera (Schltdl. & Cham.) Barneby, 1973 |
| Dalea obreniformis (Rydb.) Barneby, 1977 |
| Dalea occidentalis (Rydb.) Riley, 1923 |
| Dalea oligophylla (Torr.) Shinners, 1949 |
| Dalea orcuttii S. Watson, 1885 |
| Dalea ordiae A. Gray, 1882 |
| Dalea oreophila (Cory) Cory, 1947 |
| Dalea ovalifolia Ortega, 1797 |
| Dalea ovalifolia G. Don, 1832 |
| Dalea painteri (Rose) Bullock, 1939 |
| Dalea palmeri (Rose) Riley, 1923 |
| Dalea parrasana Brandegee, 1911 |
| Dalea parryi Torr. & A. Gray, 1868 |
| Dalea pectinata Kunth, 1819 |
| Dalea pedunculata Pursh, 1814 |
| Dalea peninsularis (Rose) Bullock, 1939 |
| Dalea phleoides (Torr. & A. Gray) Shinners, 1949 |
| Dalea pilifera (Rydb.) Bullock, 1939 |
| Dalea pinetorum Gentry, 1950 |
| Dalea pinetorum var. anilantha Barneby, 1977 |