ABIETINA Peck, Annual Rep. New York State Mus. 54: 145, pl.72, figs. 1-11. 1901.
ACICULOCYSTIS Kauffman ex Bills and Miller, Mycologia 76: 990, figs. 5, 23-26, 45, 46. 1984.
ADMIRABILIS Beardslee and Burlingham, Mycologia 31: 493. 1939.
AERUGINASCENS Peck, Annual Rep. New York State Mus. 53: 843. 1900.
AFFINIS Burlingham, Mycologia 16: 22, pl.5, fig. 8. 1924.
ALACHUANA Murrill, Mycologia 30: 362. 1938.
ALBELLA Peck, Annual Rep. New York State Mus. 50: 101. 1897.
ALBICLAVIPES Murrill, Lloydia 8: 263. 1945.
ALBIDA Peck, New York State Mus. Bull. l(no. 2): 10. 1887.
ALBIDULA Peck, Bull. Torrey Bot. Club. 25: 370. 1898.
ALBIDICREMEA Murrill, J. Elisha Mitchell Sci. Soc. 55: 369. 1939.
ALBIFLAVESCENS Murrill, Bull. Torrey Bot. Club. 66: 154. 1939.
ALBIMARGINATA Murrill, Lloydia 7: 309. 1944.
ALBIDULIFORMIS Murrill, Lloydia 6: 209. 1943.
ALCALINICOLA Burlingham, Mycologia 16: 18, pl. 5, fig. 2. 1924.
ALUTACEA (Pers.) Fr. subsp. ROMELLII (Maire) Singer form INTEGRELLA Singer, Bull. Soc. Mycol. France. 54: 153. 1938.
ALUTACEA (Pers.) Fr. subsp. ROMELLII (Maire) Singer form PSEUDOOLIVASCENS Singer, Bull. Soc. Mycol. France. 54: 153. 1938.
ALUTACEIFORMIS Murrill, Lloydia 6: 210. 1943.
AMERICANA (Singer) Singer, Bull. Soc. Mycol. France 55: 264. 1939.
AMNICOLA Singer in Singer et a1., Beih. Nova Hedwidgia 77: 269, fig. 25. 1983.
AMYGDALOIDES Kauffman, Agaricaceae of Michigan I: 162. 1918.
ANISATA Murrill, Lloydia 7: 310. 1944.
ANGUSTISPORA Bills, Mycotaxon 25: 607-620.
ANOMALA Peck, Annual Rep. New York State Mus.. 50: 99. 1897.
AOSMA Singer, Kew Bull. l952: 298. 1952.
APPALACHIENSIS Singer, Sydowia 2: 39. 1948.
ARNOLDAE Murrill, Bull. Torrey Bot. Club. 67: 57. 1940.