| Papuzilla Ridl., 1916 |
| Parrasia Greene, 1895 |
| Parrasia camporum (A. Gray) Greene, 1895 |
| Parrasia linearifolia (S. Watson) Greene, 1895 |
| Paysonia O'Kane & Al-Shehbaz, 2002 |
| Paysonia lasiocarpa (Hook. & A. Gray) O'Kane & Al-Shehbaz, 2002 |
| Paysonia lasiocarpa subsp. berlandieri (A. Gray) O'Kane & Al-Shehbaz, 2002 |
| Paysonia lasiocarpa subsp. heterochroma (S. Watson) O'Kane & Al-Shehbaz, 2002 |
| Paysonia lasiocarpa subsp. lasiocarpa (Hook. & A. Gray) O'Kane & Al-Shehbaz, 2002 |
| Peltarieae Caruel, 1893 |
| Pendulina Willk., 1852 |
| Pennellia Nieuwl., 1918 |
| Pennellia hunnewellii Rollins, 1980 |
| Pennellia juncea (O.E. Schulz) Rollins, 1980 |
| Pennellia lasiocalycina (O.E. Schulz) Rollins, 1980 |
| Pennellia longifolia (Benth.) Rollins, 1960 |
| Pennellia mcvaughii Rollins, 1979 |
| Pennellia micrantha (A. Gray) Nieuwl., 1918 |
| Pennellia microsperma (Rollins) R.A. Price, C.D. Bailey & Al-Shehbaz, 2001 |
| Pennellia patens (O.E. Schulz) Rollins, 1960 |