| Eupatorium phoenicolepis B.L. Rob., 1900 |
| Eupatorium phoenicolepis var. guatemalensis B.L. Rob., 1907 |
| Eupatorium photinum B.L. Rob., 1900 |
| Eupatorium pichinchense Kunth, 1818 |
| Eupatorium pinabetense B.L. Rob., 1901 |
| Eupatorium pinetorum L.O. Williams & A. Molina, 1975 |
| Eupatorium pithecobium B.L. Rob., 1926 |
| Eupatorium pittieri Klatt, 1892 |
| Eupatorium platyphyllum B.L. Rob., 1900 |
| Eupatorium pleianthum B.L. Rob., 1901 |
| Eupatorium plethadenium Standl. & Steyerm., 1944 |
| Eupatorium polopolense B.L. Rob., 1920 |
| Eupatorium polybotryum DC., 1836 |
| Eupatorium populifolium Kunth, 1820 |
| Eupatorium porphyranthemum A. Gray, 1880 |
| Eupatorium porriginosum B.L. Rob., 1925 |
| Eupatorium pratense Klatt, 1892 |
| Eupatorium pringlei B.L. Rob. & Greenm., 1895 |
| Eupatorium prionobium B.L. Rob., 1901 |
| Eupatorium prunellifolium Kunth, 1820 |