824 THE AGARICACEAE OF MICHIGAN 



appears ou tamarack and perhaps always ou remains of wood of 

 coniferous origin. Here it shows a marked variation from the 

 typical plant as it appears on pine and hemlock; the gills are dis- 

 tant, always pruinose, and the stem is also pruinose and often solid. 

 The typical stem of the plant from coniferous regions is usually 

 attenuated below, but in the plant of the non-coniferous regions the 

 stem is equal. The plants of non-coniferous regions are larger and 

 the surface of the cap somewhat rivulose. Hard has illustrated a 

 species (Mushrooms, Figure 98, p. 123, 1900) which he refers to O. 

 caespitosa Bolt. It seems probable that this is a var. of 0. campa- 

 nella, perhaps var. terrestris Quel. Peck says its mycelium is re- 

 garded as destructive to the wood of coniferous trees. 



884. Omphalia umbratilis Fr. 



Syst. Myc, 1821. 



Illustrations : Fries, Icones, PL 77, Fig. 3. 

 Cooke, 111., PI. 274. 



"PILEUS 2-2.5 cm. broad, campanulate to convex, then umbili- 

 cate, glabrous, hygrophanous, umber-fuscous (moist), hoary when 

 dry, margin somewhat striate. FLESH submembranaceous. GILLS 

 adnato-decurrent, broad, crowded, becoming fuscous. STEM 2-5 

 cm. long, 2 mm. thick, equal, tough, stuffed then tubular, glabrous, 

 dark fuscous to blackish. SPORES 6-7x4-5 micr." (Britz.) 



Reported by Longyear. Chandlers. June. Rare. 



Said to be gregarious on the ground, and imitating in color the 

 blackish species of Collybia, like G. atratus and C. ambustus. 



