| Pterocaulon virgatum (L.) DC., 1836 |
| Pteronia L., 1763 |
| Pteronia porophyllum Cav., 1794 |
| Pteroniinae G.L. Nesom, 2020 |
| Ptilomeris Nutt., 1841 |
| Ptilomeris coronaria Nutt., 1841 |
| Ptilostephium Kunth, 1818 |
| Ptilostephium coronopifolium Kunth, 1818 |
| Pyrethrum Medik., 1775 |
| Pyrethrum parthenium (L.) Sm., 1800 |
| Pyrrhopappus DC., 1838 |
| Pyrrhopappus carolinianus (Walter) DC., 1838 |
| Pyrrhopappus pauciflorus (D. Don) DC., 1838 |
| Pyrrhopappus sessaeanus DC., 1838 |
| Pyrrocoma Hook., 1833 |
| Pyrrocoma menziesii Hook. & Arn., 1838 |
| Rafinesquia Nutt., 1841 |
| Rafinesquia californica Nutt., 1841 |
| Rafinesquia neomexicana A. Gray, 1853 |
| Ratibida Raf., 1817 |