268 THE AGARICACEAE OF MICHIGAN 



and when it again becomes moist. On drying the cap finally be- 

 comes grayish-white; mature specimens during wet weather assume 

 a livid-gray appearance, which is also the case when kept moist in a 

 box after collecting. It is a rather small, unimportant plant of 

 swamps where it is sometimes plentiful. 



Psathyra Fr. 

 (From the Greek, psathyros, friable.) 



Purple-brown-spored. Stem with a cartilaginous cortex, rigid- 

 fragile, slender and hollow. Gills adnate or adnexed. Margin of 

 pileus at first straight. Veil either none or universal, in the latter 

 case leaving delicate Hecks or fibrils over the surface of the young 

 pileus and stem. Pileus hygrophanous. 



Putrescent, terrestrial or on decayed wood. The genus corre- 

 sponds to Mycena of the white-spored group in that the stem is 

 somewhat cartilaginous and the margin of the pileus is at first 

 straight and appressed to the stem; the pileus is therefore likely 

 to be persistently campanulate as in Mycena. See Plate LVI. The 

 species are slender, fragile and hygrophanous. It is somewhat 

 difficult to tell some of the species from Psilocybe except in the 

 presence of very young stages showing the straight margin of the 

 cap. 



The genus naturally falls into two sections, the first composed 

 of species without cortina or universal veil; the second, where the 

 young plants are surrounded by a delicate, usually white, fibrillose 

 or flocculose universal veil. The veil breaks up early and leaves 

 thin superficial flecks or scales on cap and stem, or sometimes 

 merely white fibrils, which are unrecognizable in age or after rains. 

 The species occur rather infrequently, but quite a number have 

 been found in the state. Of these only a part are here presented, 

 as it has been impossible to identify the others with any certainty. 

 Their edibility has not been reported. 



Key to the Species 



(A) Pileus at first with fibrillose flecks or hairs. 



(a) Densely caespitose; pileus even, slightly pelliculose; stem short. 



262. P. microsperma Pk. 

 (aa) Gregarious; pileus and stem superficially white-hairy at first. 

 261. P. semivestita Berk. 

 (AA) Pileus glabrous; stem polished. 



(a) Caespitose on or near wood; pileus striatulate when moist; stem 

 long. 259. P. umbonata Pk. 



