86 THE CHICAGO ACADEMY OF SCIENCES 



CREPIDOTUS. 



Stature various, irregular without a manifest veil; pileus 

 eccentric, lateral or resupinate; spores yellowish-brown. Growing 

 on wood, rarely on mosses; plants commonly with soft flesh. 



Plant with a distinct stem C. tiliophilus. 



Plant sessile or nearly so 1 



1. Pileus glabrous or only slightly villous 



at the base* 2 



1. Pileus not glabrous 3 



2. Lamellae very narrow, decurrent C. applanatus. 



2. Lamellae broader, rounded behind C. malachius. 



2. Lamellae decurrent to the base C. mollis. 



3. Pileus white with a white villosity C. herbarum. 



3. Pileus squamose with a tawny to- 



mentum C. fulvotomentosus 



3. Pileus reddish-yellow with a yellowish 



tomentum C. dorsalis. 



Crepidotus tiliophilus Pk. 



Pileus moderately thin, convex, minutely pulverulent, hy- 

 grophanous, watery-brown and striatulate on the margin when 

 moist, dingy buff when dry. 



Lamellae rather broad, subdistant, rounded behind, adnexed, 

 colored like the pileus, becoming ferruginous-cinnamon. 



Stem solid, often curved, pruinose, with a white pubescence at 

 the base. 



Pileus 12 to 24 mm. broad; stem 4 to 8 mm. long, 2 mm. 

 thick; spores subelliptical, brownish-ferruginous, 6 to 7.5 x 4 to 5 /x. 



On bark of living Crataegus, open woods, Glen Ellyn. August. 

 Spores somewhat irregular in shape, 6 to 8 /*.; otherwise our 

 specimens agree with the description. The plant from which 

 Prof. Peck's description was written grew upon dead trunks and 

 branches of Tilia americana. 

 Crepidotus applanatus Fr. 



Pileus very thin, variable in shape, suborbicular, reniform, 

 cuneiform or spathulate, plane or convex, sometimes slightly 

 depressed behind, sessile or prolonged behind into a short com- 

 pressed white-tomentose stem-like base, glabrous, hygrophanous, 

 watery -white and striatulate on the margin when moist, white 

 when dry. 



Lamellae very narrow, linear, crowded, decurrent, white, 

 becoming cinnamon. 



Pileus 12 to 24 mm. long, 8 to 20 mm. broad; spores globose, 

 5 to 6 /u. 



On stumps, woods, Glen Ellyn. July. 

 Crepidotus malachius B. & C. 



Gregarious but scattered, horizontal; pileus smooth, white, 

 cuneiform, subflabellate; flesh rather thick behind, very thin in 

 front. 



