Murrill: Dark-spored Agarics 



211 



1 6. Agaricus argenteus Braendle in Peck, Bull. Torrey Club 26 : 



68. 1899 



Pileus thin, convex, becoming nearly plane, 2.5-5 cm - broad; 

 surface slightly silky or glabrous, pale-grayish-white or grayish- 

 brown, shining with a silvery luster when dry; margin sometimes 

 striate, at first incurved, often revolute with age; context edible, 

 whitish, becoming blackish when cut ; lamellae crowded, free, at 

 first brownish, becoming blackish-brown or black with age ; spores 

 broadly ellipsoid, 7-10 x 6/x; stipe short, glabrous, solid, often 

 narrowed toward the base, 2.5-4 cm. long, 4-8 mm. thick; annulus 

 slight, evanescent. 



Type locality : Washington, District of Columbia. 



Habitat : Lawns and grassy places in rich soil. 



Distribution : Known only from the vicinity of Washington. 



Collected by F. J. Braendle, who says that the drying specimens 

 emit a strong but not unpleasant odor. The species appears after 

 rains from April to November, and is often associated with Stro- 

 pharia bilamellata. 



17. Agaricus rutilescens Peck, Bull. Torrey Club 31 : 180. 



1904 



Pileus fleshy, firm, convex with incurved margin, becoming 

 nearly plane, 2.5-6 cm. broad ; surface even or sometimes rimose 

 and minutely fibrillose, dingy-white, becoming ferruginous, red- 

 dish-brown, or bay on drying ; context whitish changing to reddish 

 when cut or broken ; lamellae crowded, narrow, free, reddish be- 

 coming blackish-brown ; spores broadly ellipsoid, 7-8 x 5-6 fi ; stipe 

 equal or nearly so, firm, stuffed, silky, white, changing to reddish 

 when wounded, frequently abruptly bulbous at the base, with a 

 white veil often adhering partly to the margin of the pileus and 

 partly to the stipe, 5-10 cm. long, 6-10 mm. thick. 



Type locality : Denver, Colorado. 

 Habitat : On manured ground in pastures. 

 Distribution : Vicinity of Denver, Colorado. 

 Collected by E. B. Sterling on June 7, 1902. The types are well 

 preserved at Albany. 



18. Agaricus brunnescens Peck, Bull. Torrey Club 27: 16. 



1900 



Pileus thick, firm, hemispheric, becoming convex or nearly plane, 

 gregarious, 5-10 cm. broad; surface fibrillose, sometimes slightly 



