PERLACTEA Murrill, Lloydia 6: 213. 1947.
PERPLEXA Burlingham, Mycologia 10: 96. 1918.
PERSOBRIA Kauffman ex Singer, Bull. Soc. Mycol. France 55: 228. 1939.
PERVIRGINEA Murrill, Lloydia 8: 268. 1945.
PINETORUM Murrill, Bull. Torrey Bot. Club 66: 155. 1939.
PINICOLA Murrill, Lloydia 6: 213. 1943.
PINOPHILA Murrill, Quart. J. Florida Acad. Sci. 8: 182. 1945.
PLACITA Burlingham, Mycologia 28: 253, fig. l-a. 1936.
PLUVIALIS Singer in Singer et al., Beih. Nova Hedwidgia 77: 221, figs. 11-13. 1983.
POLYCYSTIS Singer, Bull. Soc. Mycol. France 55: 238. 1939.
POLYPHYLLA Peck, Bull. Torrey Bot. Club 25: 370. 1898.
PRAECLAVIPES Murrill, Lloydia 6: 213. 1943.
PRAECOMPACTA Murrill, Lloydia 7: 312. 1944.
PRAEFORMOSA Murrill, Lloydia 6: 214. 1943.
PRAEFRAGILIS Murrill, Lloydia 8: 269. 1945.
PRAEPALUSTRIS Murrill, Lloydia 8: 269. 1945.
PRAERUBRA Murrill, Lloydia 6: 214. 1943.
PRAERUBRICEPS Murrill, Lloydia 6: 215. 1943.
PRAETENUIS Murrill, Lloydia 6: 215. 1943.
PRAEUMBONATA Burlingham, Mycologia 13: 134, fig. 5. 1921.
PSEUDOFOETENS Murrill, Lloydia 7: 312. 1944.
PSEUDOLEPIDA Singer, Bull. Soc. Mycol. France 55: 251. 1939.
PUELLARIS UMBONATA Peck, Bull. Torrey Bot. Club 29: 557. 1902.
PULVERULENTA Peck, Bull. Torrey Bot. Club 29: 70. 1902.
PULCHRA Burlingham, Mycologia 10: 95. 1918.
PUIGGARII (Spegazzini) Singer, Lilloa 22: 793. 1949. nomen nudum.
PUIGGARII (Spegazzini) Singer, Lilloa 23: 239. 1950.