| Eragrostis orcuttiana Vasey, 1893 |
| Eragrostis oreophila L.H. Harv., 1954 |
| Eragrostis oxylepis (Torr.) Torr., 1857 |
| Eragrostis oxylepis var. beyrichii (J.G. Sm.) Shinners, 1952 |
| Eragrostis pallida Vasey, 1893 |
| Eragrostis palmeri S. Watson, 1883 |
| Eragrostis panamensis J. Presl, 1830 |
| Eragrostis panicoides (J. Presl) Steud., 1854 |
| Eragrostis papi Gand., 1919 |
| Eragrostis pappiana (Chiov.) Chiov., 1908 |
| Eragrostis parviglumis Hochst. ex Steud., 1854 |
| Eragrostis parvula Steud., 1854 |
| Eragrostis patula (Kunth) Steud., 1840 |
| Eragrostis pauciflora Trin. ex E. Fourn., 1886 |
| Eragrostis pectinacea (Michx.) Nees, 1841 |
| Eragrostis pectinacea (Michx.) Steud., 1854 |
| Eragrostis pectinacea var. miserrima (E. Fourn.) Reeder, 1986 |
| Eragrostis pectinacea var. pectinacea (Michx.) Nees, 1841 |
| Eragrostis pectinacea var. sparsihirsuta Farw., 1927 |
| Eragrostis pectinacea var. spectabilis (Pursh) A. Gray, 1856 |