DARK-SPORED AGARICS— III 



Agaricus 



William A. Murrill 



In my last article Gomphidius and Stropharia were discussed. 

 The genus Agaricus, as at present limited, differs from them both 

 in having free lamellae. 



Agaricus L. Sp. PI. 1171. 1753 



Pratclla S. F. Gray, Nat. Arr. Brit. PI. 1 : 626. 1821. 

 Psalliota Quel. Champ. Jura Vosg. 107. 1872. 



This genus, distinguished among brown-spored gill-fungi by a 

 fleshy stipe, free lamellae, and the presence of an annulus, has 

 received much attention because of the important edible species in 

 it. The different species are usually not very well characterized, 

 being much the same in shape and color and differing very little in 

 spore characters. A number of new ones have been described 

 from tropical America and from the Pacific coast. See Myco- 

 logia for March, 1918, and for November, 1912. 



Pileus white or yellowish or becoming so ; tinged 

 with lilac in A, variabilis and sometimes 

 with rose in A. comtulus. 

 Pileus 2-5 cm. broad. 



Pileus white, becoming yellowish. 

 Stipe 4 mm. thick. 

 Stipe 10 mm. thick. 

 Pileus yellow, becoming nearly white. 

 Pileus larger, usually 5-15 cm. broad. 

 Pileus white, unchanging. 

 Surface squamose. 

 Surface deeply rimose-areolate. 

 Surface smooth, glabrous or fibrillose. 

 Pileus 7-12 cm. broad. 

 Pileus usually 5-7 cm. broad. 

 Annulus cup-like. 

 Annulus not cup-like. 

 Pileus white, becoming yellowish ; or 

 tinged with yellow at the center. 

 Pileus lilac-tinted when young, yel- 

 lowish when older. 

 Pileus yellowish at the center. 

 Pileus 5-10 cm. broad. 



200 



1. A. comtulus. 



2. A. alabamensis. 



3. A. comtuliformis. 



4. A. solidipes. 



5. A. praerimosus. . 



6. A. pilosporus. 



7. A. chlamydopus. 



8. A. campester. 



9. A. variabilis: 

 10. A. Rodmani. 



