The North American species of Psathyrella.

PSATHYRELLA (Fries) Quelet, Mem. Soc. Emul. Montbeliard II, 5: 152. 1872
(Champ. Jura et Vosges 1: 152. 1872)
Agaricus (Psathyrella) Fries, Epicr. Syst. Mycol. 237. 1838.
Psathyra Kummer, Fiihr. Pilzk. 20. 1871 (non Spring, 1818).
Psathyra (Fr.) Quelet, Champ. Jura et Vosges, 148. 1872.
Hypholoma (Fr.) Quelet, Champ. Jura et Vosges, 143. 1872.
Pannucia Karsten, Bidr. Finl. Nat. Folk 32: xxvi. 1879.
Drosophila Quelet, Enchir. Fung. 115. 1886.
Lacrymaria Patouillard, Hymen. Europ. 122. 1887.
Astylospora Fayod, Ann. Sci. Nat. Bot. VII, 9: 376. 1889.
Atylospora Murrill, Mycologia 10: 18. 1918.
Glyptospora Fayod, Ann. Sci. Nat. Bot. VII, 9: 377. 1889.
Pluteopsis Fayod, Ann. Nat. Bot. VII, 9: 377. 1889.
Cortiniopsis Schroeter in Cohn, Kryptg. Fl. Schles. Pilze, 566. 1889.
Gymnochilus Clements, Bot. Surv. Nebr. 4: 23. 1896. (non Blume 1858).
Hypholomopsis Earle, Bull. N. Y. Bot. Gard. 5: 436. 1909.
Psalliotina Velenovsky, Novitates Mycol. 155. 1939.
Panaeolina Maire, Trebl. Mus. Cien. Nat. Barcelona 15: 109. 1933.
Psilocybe Fayod, Ann. Sci. Nat. Bot. VII, 9: 377. 1889.
The diagnostic features of Psathyrella are as follows: spore print typically
some shade of cocoa-color to chocolate-black, or dull brick red, or avellaneous
(pinkish gray); spores typically with a germ pore visible to some extent under
an oil immersion lens and in many species causing the spore apex to be truncated;
spore wall at least slightly thickened; pileus typically thin and fragile, the
cuticle composed of inflated short cells or pedicellate cells in a palisade or consisting of a mixture of both; veil development various: from none at all to an
outer and inner veil of significant proportions; clamp connections usually
present; sporulating basidia often projecting beyond the basidioles; basidioles
with a tendency to inflate in some species to form brachybasidioles or the latter
becoming differentiated by early maturity.
Type. Psathyrella gracilis.
Observations. Although color is not regarded as an important generic
character, it is true that by far the majority of the species range from pale
clay color to dark liver brown in the moist state, and fade to pale tan, honey
brown or nearly white. As is found in Cortinarius, the size of the basidiocarps
varies between species from minute to those having pilei 15 cm wide, but most
are 2-7 cm wide and with the stipe 1-6 mm thick. The basidiocarps are very
short-lived, lasting one to a few days ordinarily or slightly longer for large
basidiocarps. For most species there is one major period of spore production.
Key to the Subgenera of Psathyrella
1. Spores ornamented (observe under low-power oil immersion of NA 0.95 or 1.25);
veil absent; brown basidiole-like bodies imbedded in the hymenium (see 66.
P. neotropica also). Panaeolina.
1. Not as above. 2
2. Some of the pleurocystidia in fascicles of 2-4 and/or spores ornamented;
lamellar surfaces more or less mottled at maturity. Lacrymaria.
2. Not as above. 3
3. Parasitic on species of Coprinus. Mycophila.
3. Not parasitic. 4
4. Pileus innately fibrillose to squamulose and the fibrils colored; spores often
angular to subangular in face view (but see 81. P. subagraria also).
Psathyroides.
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