Murrill : Dark-Spored Agarics 



269 



Psathyra semivestita (Berk. & Br.) Sacc. Syll. Fung. 5: 1071. 

 1887. (Agaricus semivestitus Berk. & Br. Ann. Mag. Nat. Hist. 

 III. 7: 376. 1861.) Described from England and reported by 

 Kauffman from Michigan, growing gregariously on horse manure. 

 He says Peck's P. vestita is very similar, and Peck says his species 

 differs in color and in being wholly clothed when young with white, 

 floccose fibrils. 



Psathyra silvatica Peck, Ann. Rep. N. Y. State Mus. 42: 116. 

 1889. The types from North Elba are attached to a sheet at 

 Albany and marked in Peck's handwriting " equal Tubaria silvatica 

 Peck." The species is omitted from Peck's later account of the 

 New York species of Psathyra. 



Psathyrella (Fries) Quel. Champ. Jura Vosg. 122. 1872 



Agaricus § Psathyrella Fries, Epicr. Myc. 237. 1838. 



Characterized by black spores and a straight, appressed margin 

 when young. It is best known, perhaps, through its interesting 

 little representative, Psathyrella minutula, which is widely distrib- 

 uted. In Mycologia for January, 1918, the six species known 

 from tropical North America were discussed, five of them being 

 there described as new. 



Stipe 1-5 cm. long. 



Pileus white or gray, furfuraceous ; hymenophores 



densely gregarious or cespitose. 

 Pileus bluish-white, changing to sepia-brown on 



1. P. minutula. 



drying except at the apex. 

 Pileus reddish-cinereous, becoming paler on dry- 



2. P. leucostigma. 



ing; stipe scarcely i mm. thick. 

 Pileus some shade of brown. 



3. P. tenera. 



Pileus 2-4 mm. broad. 



4. P. minima. 



Pileus 8-12 mm. broad; decorated with erect 



hairs. 



5. P. hirta. 



Pileus 1-3 cm. broad. 



Stipe 3-4 mm. thick. 

 Stipe 1-2 mm. thick. 



Stipe white, glabrous. 



Stipe pale-brown, fibrillose. 

 Stipe 5-15 cm. long. 



7. P. betulina. 



8. P. Bartholomaei. 



6. P. castaneicolor. 



Pileus bluish-white, with yellow disk. 

 Pileus whitish, becoming grayish. 



9. P. gracillima. 

 10. P. debilis. 



