| Castilleja palmeri Eastw., 1909 |
| Castilleja papilionacea G.L. Nesom, 1992 |
| Castilleja patriotica Fernald, 1904 |
| Castilleja pectinata M. Martens & Galeotti, 1845 |
| Castilleja pectinata var. purpusii (Brandegee) J.M. Egger, 2008 |
| Castilleja perelegans G.L. Nesom, 1992 |
| Castilleja porphyrosceptron G.L. Nesom, 1992 |
| Castilleja pringlei Fernald, 1905 |
| Castilleja pterocaulon N.H. Holmgren, 1976 |
| Castilleja purpusii Brandegee, 1904 |
| Castilleja quiexobrensis G.L. Nesom, 1995 |
| Castilleja racemosa (Breedlove & Heckard) T.I. Chuang & Heckard, 1991 |
| Castilleja retrorsa Standl., 1909 |
| Castilleja rhizomata N.H. Holmgren, 1976 |
| Castilleja rigida Eastw., 1909 |
| Castilleja roei Crosswh., 1970 |
| Castilleja salaisolaveae J.M. Egger, Velazco & Huereca, 2022 |
| Castilleja saltensis Eastw., 1909 |
| Castilleja scabridula Eastw., 1909 |
| Castilleja schaffneri Hemsl., 1882 |