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Thk Flat-cap Mushroom (Edible) 

 Agariciis l^lacoinyccs Peck 



Agaricus f^lacoiiiyccs occurs in lawns, parks, and the borders of 

 woods from June to September. It is sometimes said to be associated 

 with hemlock trees, l)ut I find it abundantly at Urbana where hemlock 

 does not occur, and. indeed sometimes it is not associated with any 

 kind of tree, being found in open grassy places. 



The cap is 5 to 12 cm. (2 to 5 inches) broad and rather thin. It 

 is at first broadly ovate, then convex, and finally, when fully expanded, 

 it is quite flat. In voung specimens the surface is (juite uniform brown 

 in color, but as the cap expands the surface layer breaks up into nu- 

 merous small brown scales and the ground-color then becomes white 

 or vellowish white except at the center, where there is always a cir- 

 cular patch that is nearly smooth and uniformly brown. 



The gills are close together and free from the stem. They are at 

 first white but verv soon become pink, and when old they are blackish 

 l)ro\vn. The spores are l)lackish brown with a tinge of puri)le. 



The stem is 5 to 15 cm. ( 2 to 6 inches) long, rather slender, some- 

 times hollow, and somewhat bulbous at the base. It is white or whit- 

 ish, luit the l)ulb is sometimes tinged with yellow. The inner veil is 

 quite interesting. It is double, that is, it consists of two layers, loosely 

 joined together by threads. In young specimens it is found stretched 

 from the margin of the cap to the stem. As the cap expands, the 

 lower layer is usually torn into quite regular radiating portions. Later 

 the upper portion is torn loose from the cap and the whole forms a 

 broad ring on the stem. There is no \'ol\a. 



This is a very prettv mushroom, and while the caps are rather thin 

 they are of excellent flavor and can be used in any way in which the 

 cultivated mushroom is used. 



Collected in Champaign county. 



