128 THE AGARICACEAE OF MICHIGAN 



natural coloring and gills, but differs in the change which the flesh 

 undergoes when bruised. Authors consider IZ. adusta to have a mild 

 taste and if this is true our plant differs also in this respect. The 

 gills are usually markedly crowded and narrow, while those of R. 

 nigricans are broad and subdistant. The latter is more common 

 in coniferous regions, while B. densifolia has so far been found in 

 Michigan only in frondose woods. Maire (Bull. Soc. Myc. France, 

 26, p. 87) states that R. densifolia lacks the hair-like sterile cells on 

 the edge of the gills; that they are abundant in R. nigricans and 

 less numerous in R. adusta. In our specimens of R. densifolia they 

 were abundant, which would indicate that this is not a very con- 

 stant character. 



102. Russula adusta Fr. 



Epicrisis, 1836-38. 



Illustrations: Cooke, 111., PI. 1051. 



Michael, Fiihrer f. Pilzfreunde, Vol. II, No. 64. 

 Ricken, Blatterpilze, PL 15, Fig. 3. 



"PILEUS 5-7 cm. broad, convex then depressed or subinfundi- 

 buliform, ivhite or tvhitish, becoming brownish or sooty-gray, glab- 

 rous, dry, even. FLESH compact, white, not changing ichen 1)ruised. 

 GILLS adnate to subdecurrent, thin, close, short and long alter- 

 nating, narrow, white becoming sordid. STEM 2-5 cm. long, about 

 1.5 cm. thick, short, solid, equal or subequal, glabrous, even, white 

 then sooty-gray. SPORES subglobose, slightly echinulate, 6-9 micr., 

 white in mass. Taste mild. Odor slight." 



Gregarious or solitary. On the ground in mixed woods of north- 

 ern Michigan. July-September. Infrequent. 



The smaller size, unchanging flesh when bruised, and thin close 

 gills characterize it. At first the whole plant is nearly white, but 

 it gradually takes on a grayish or sooty cast. Michael, who gives 

 an excellent figure, says it has a rather strong odor which is almost 

 nauseating. This seems not to have been noticed by others. In 

 Europe, also, it is said to be soon attacked by grubs especially in 

 the stem ; as the same insects do not always occur in this country, 

 such facts are only of local interest. It usually hugs the ground 

 closely. 



