-„., THE AGARICACEAE OF MICHIGAN 



fuse the student. Sometimes the pileus is provided with a little 

 umbo, sometimes the plants attain a larger size than that given. 

 A form growing on sphagnum is especially large. 



Bolbitius Fr. 

 I From the Greek, bolbiton, cow's-dung.) 



Ochre-brown to rusty-ochraceous-spored. Gills dissolving some- 

 what in wet weather, narrowly attached. Margin of pileus at first 

 straight; flesh very thin. Stem fragile and slender. Partial veil 

 vcr\ evanescenl or none. 



Putrescent, delicate, dung-inhabiting fungi, with hollow, elongated 

 stems, with gills which dissolve more or less into a soft mass in age 

 and very thin caps which usually split on the margin. They approach 

 the genus Coprinus in habit and in the structure of the hymenium, 

 differing in the rusty-ochraceous spores. They have something of 

 the appearance of Galera, but their gills are clearly differ- 

 ent. Only three species are included below. Some consider Plu- 

 teolus reticulatus to be a better species of Bolbitius. The genus 

 Pluteolus, in fact, differs only in degree from Bolbitius. Species 

 with free gills and the stem separable from the pileus are referable 

 to Pluteolus ; species with gills more or less narrowly attached and 

 with a tendency of the gills to become soft, belonging to Bolbitius. 

 But apparently these characters vary or intermediate forms may 

 occur. The gills of Pluteolus reticulatus are sometimes narrowly 

 adnate and those of some species of Bolbitius are free in occasional 

 specimens. The texture of the stem in both genera is different from 

 thai of the pileus and the stem is more or less separable. The pileus 

 is \ iscid or slightly so in nearly all species of both genera. In spite 

 of these facts, the nature of the gills of Bolbitius remains a real 

 distinguishing character and the genus Pluteolus will be retained in 

 ii< proper place. 



Key to the Species 

 (See Pluteolus) 



