| Pentarrhaphis polymorpha (E. Fourn.) Griffiths, 1912 |
| Pentarrhaphis scabra Kunth, 1816 |
| Pentastachya Steud., 1841 |
| Pentatherum Nábelek, 1929 |
| Pereilema J. Presl, 1830 |
| Pereilema beyrichianum (Kunth) Hitchc., 1927 |
| Pereilema brasilianum Trin., 1841 |
| Pereilema ciliatum E. Fourn., 1886 |
| Pereilema crinitum J. Presl, 1830 |
| Pereilema crinitum var. cirratum E. Fourn., 1886 |
| Pereilema crinitum var. crinitum J. Presl, 1830 |
| Pereilema setarioides E. Fourn., 1886 |
| Perlaria Heist. ex Fabr., 1763 |
| Perulifera A. Camus, 1928 |
| Peyritschia E. Fourn., 1886 |
| Peyritschia deyeuxioides (Kunth) Finot, 2003 |
| Peyritschia humilis (Louis-Marie) Finot, 2003 |
| Peyritschia koelerioides (Peyr.) E. Fourn., 1886 |
| Peyritschia pinetorum (Swallen) Finot & P.M. Peterson, 2006 |
| Peyritschia pringlei (Scribn.) S.D. Koch, 1979 |