82 ELEVENTH REPORT. 



fact seems to be that it differs in such points as are usually considered specific 

 in this group, from all of them. Whether we call it a species or a variety 

 makes no difference for purposes of identification, and its phylogenetic re- 

 lationship can at present hardly be worked out. 



40. RUSSULA ALBIDULA Pk. 



(The little white Russula.) 



PiLEUS 2.5-5 cm. broad, ivhite, broadly convex, glabrous, the pellicle 

 viscid and separable when fresh, the margin even. Flesh white, subfragile. 

 Gills white, rather crowded, adnexed, not broad, of equal length, some basi- 

 furcate, interspaces venose. Stem 2.5-4 cm. long, 8-12 mm. thick, white, 

 ecjual, spongy-stuffed, even. Spores white in mass, subglobose, 7-10 micr. 

 Taste acrid. Odor none. Solitary. In oak woods. Ann Arbor. July 

 and August. 



In dried specimens the pileus and gills are ochraceous to yellowish, the 

 stem whitish. The taste and viscidity seem to be the only marked differences 

 between this species and the other two white Russulas of Peck, R. albida 

 and R. albella. All three are rather fragile, while the European R. lactea 

 is a compact firm plant with thick, broad, distant gills. R. emetica has a 

 white variety which is very acrid and fragile, but whose striations on the 

 margin of the cap are like those of R. emetica. 



B. TASTE MILD. 



41. Russula albida Pk. Russula albella Pk. 



(The whitish Russula.) 



Pileus 3-6 cm. broad, thin, fragile, broadly convex to plane, slightly 

 depressed in the centre, white or whitish, even or slightly striate on the margin, 

 not shining. Flesh white, fragile. Gills white or whitish, thin, moderately 

 close, entire, ecivial, not broad, broadest in front, rarely forked at base, adnata 

 or subdecurrent. Stem 2.5-6 cm. long, white, subequal, glabrous, spongy- 

 stuffed or solid. Spores about 8 micr. diam., white. Taste mild or slightly 

 bitterish. 



Sohtary. Hemlock or mixed woods in the northern peninsula. July and 

 August. 



Peck's description of the two species named above differs in minor partic- 

 ulars from our plants. The pileus of R. albida has a viscid, separable pellicle, 

 while that of R. albella is dry. R. albida is said to have a "slightly bitterish 

 or unpleasant taste," while our plants were sometimes bitterish, sometimes 

 tardily and slightly acrid. R. albida is described with stuffed or hollow stem; 

 in one of my collections the stem was solid, in another it was spongy-stuffed. 

 It is worth noting whether the spore prints are pure white or with yellow 

 tinge; some of Peck's specimens of R. albida had spores with a faint yellowish 

 tinge. In my specimens the whole plant is ochraceous when dried. As these 

 species occur so seldom and far apart, it is difficult to obtain exact data with 

 regard to their characters. R. anomola Fr. and R. albidula differ in the acrid 

 taste. 



