PUNGENS Beardslee, J. Elisha Mitchell Sci. Soc. 33: 196, pl. 110, 111. 1918.
PURPUREOMACULATA Shaffer, Lloydia 33: 75. 1970.
PUSILLA Peck, Annual Rep. New York State Mus. 50: 99. 1897. non Hennings, Monsunia 1: 149. 1899.
PUSILLIFORMIS Murrill, Quart. J. Florida Acad. Sci. 8: 182. 1945.
QUERCUSOLEOIDIS Singer in Singer et al., Beih. Nova Hedwigia 77: 255. fig. 20. 1983.
REDOLENS Burlingham, Mycologia 13: 133, pl. 7, fig. 6. 1921.
REGALIS Murrill, Bull. Torrey Bot. Club 67: 231. 1940.
RIMOSA Murrill, Lloydia 8: 270. 1945. non McNabb, New Zealand J. Bot. 11: 698, figs. 14, 34. 1973.
RIOGRANDENSIS Singer, Lilloa 26: 81. 1953.
ROBINSONIAE Burlingham, N. Am. Fl. 9: 221. 1915.
ROMAGNESIANA Shaffer, Mycologia 56: 217, figs. 12, 14. 1964.
ROOSEVELTIANA Murrill, Lloydia 6: 215. 1943.
ROSACEA (Pers.) S. F. Gray var. AMERICANA Singer, Bull. Soc. Mycol. France 54: 146. 1938.
ROSACEA (Pers.) S. F. Gray var. MACROPSEUDOCYSTIDIATA Grund, Mycotaxon 9: 101, figs. 3, 9, 10. 1979.
ROSEI-ISABELLINA Murrill, Lloydia 6: 216. 1943.
ROSEIPES (Secr.) Bresadola subsp. THERMOPHILA Singer, Sydowia 11: 257. 1957(1958).
ROSEITINCTA Murrill, Bull. Torrey Bot. Club 67: 278. 1940.
RUBESCENS Beardslee, Mycologia 6: 91, fig. 1. 1914.
RUBRICEPS (Kauffman) Singer, Mycologia 35: 151. 1943.
RUBRIOCHRACEA Murrill, Mycologia 4: 293, pl. 76, fig. 9. 1912.
RUBRIPURPUREA Murrill, Lloydia 6: 216. 1943.
RUBRIFOLIA Murrill, Bull. Torrey Bot. Club 67: 232. 1940.
RUBROTINCTA (Peck) Burlingham, N. Am. Fl. 9: 229. 1915.