212 THE AGARICACEAE OF MICHIGAN 



Section II. Atramcntarii. Ring imperfect, not volvate, squarh- 

 ules of pileus minute, innate. 



189. Coprinus atramentarius Fr. (Edible) 



Fries, Epicr., p. 243. 



Illustrations: Cooke, 111., PI. 622. 



Gillet, Champignons de France, No. 172. 

 Atkinson, Mushrooms, Fig. 39-42. 

 Hard, Mushrooms, Fig. 271-272. 

 Murrill, Mycolgia, Vol. 1, PL 3, Fig. 4. 



riLEUS 5-8 cm. broad when expanded, ovate then expanded, 

 firm, often lobed and plicate, grayish, silky fibrous, or minutely 

 mealy, apex brownish, often minutely squamulose. FLESH thin. 

 GILLS crowded, broad, ventricose, free, white then black, often with 

 a purplish tinge. STEM 10-15 cm. high by 1-2 cm. thick, white, silky 

 shining, hollow, ring basal, very evanescent. SPORES 11-12x5.5-6 

 micr. CYSTIDIA numerous, large, subcyliudrical. 



Common, gregarious or densely caespitose, about stumps or on 

 rich soil, but not upon dung. 



Both the smooth and the scaly, or squamulose, forms are found. 

 These characters often seem to depend upon weather conditions, the 

 smooth form being found under moist atmospheric conditions and 

 the scaly form under dry atmospheric conditions. 



Its close broad gills make it very thick and meaty in the unex- 

 panded condition. For this reason some people consider this species 

 the most desirable Coprinus for the table. 



190. Coprinus insignis Pk. 

 Teck, X. Y. State Mus. Rep. 20, p. GO, 1874. 

 Illustration: Plate XXXIII of this Report. 



PILEUS 5-7.5 cm. broad, ovate then campanulate, thin, sulcate- 

 striate to the disk, grayish brown, glabrous or with a few innate 

 fibrils, disk sometimes cracking into small areas or scales. GILLS 

 free, ascending, crowded. STEM 10-14 cm. high, 10 mm. thick, 

 hollow, slightly fibrillose, striate, white. SPORES 10x7 micr., 

 rough. 



About trees in woods. 



This plant was found but twice in low woods at Ann Arbor, It 

 resembles C. atramentarius in some respects but differs very decid- 

 edly in the distinctly warted spores. 



