| Lobelia obconica E. Wimm., 1948 |
| Lobelia occidentalis McVaugh & Huft, 1975 |
| Lobelia ocimoides Kunze, 1847 |
| Lobelia orientalis Rzed. & Calderón, 1997 |
| Lobelia palmaris Willd. ex Schult., 1819 |
| Lobelia palmeri Greene, 1889 |
| Lobelia parviflora M. Martens & Galeotti, 1842 |
| Lobelia patzquarensis Sessé & Moc., 1890 |
| Lobelia pectinata Engelm., 1848 |
| Lobelia persicifolia Cav., 1800 |
| Lobelia persicifolia var. warscewiczii (Regel) Vatke, 1874 |
| Lobelia phyllostachya Engelm., 1848 |
| Lobelia picta B.L. Rob. & Seaton, 1893 |
| Lobelia piscinula E. Wimm., 1935 |
| Lobelia plebeia E. Wimm., 1926 |
| Lobelia plumieri L., 1753 |
| Lobelia poasensis E. Wimm., 1932 |
| Lobelia poetica E. Wimm., 1926 |
| Lobelia porphyrea Rzed. & Calderón, 2001 |
| Lobelia pringlei S. Watson, 1890 |