MICHIGAN ACADEMY OF SCIENCE. 77 



28. RUSSULA PULVERULENTA Pk. 



(The mealy-dotted Russula.) 



PiLEus 3-5 cm. broad, rather rigid, then fragile, rather thin, irregularly 

 convex, soon centrally depressed or siibumbilicate, at first even on margin, 

 tubercular-striate when expended, the viscid pellicle separable on margin, 

 ochraleiicus (Sacc.)!then grayish-brown, surface dotted by small, numerous, 

 pale yellow somewhat mealy scales or jDatches. Flesh white with loose tissue. 

 Gills white, unchanged, rather close, broadest in front, few forked at base, 

 adnate, interspaces veiny. Stem 4-5 cm. long, 1-1^ cm. thick, subequal 

 or irregularly enlarged, stained or dotted with sulphur- yellow grcmules, white 

 elsewhere, spongy-stuffed becoming cavernous, rigid-fragile. Spores white 

 in mass, globose, 6-8 micr. Taste and odor somewhat disagreeable. 



Gregarious. On lawns, roadsides or margin of woods among grass, etc. 

 July to September. Southern Michigan. 



I have referred here a Russula which differs from the description of R. 

 pulverulenta Pk. in its striate pileus, less foetid odor, and from R. granulata 

 in its yellow pulverulence on the stem. Since Peck's description was made 

 from a single Michigan specimen, found by Longyear,* it is very probable 

 that the striations did not show in his plant as is often the case in fresh 

 young plants. I have ventured to amend the description from my own notes, 

 as I believe my specimens to be the same plants as Longyear's. The yellow 

 granules may possibly represent a primitive universal veil, since they occur 

 mostly on the margin of the pileus in young plants." The habitat seems to 

 he mostly in open grassy places. 



29. Russula granulata Pk. 

 (The granulated Russula.) 



This is close to R. foetens, of which it was formerly a variety. It differs 

 in the pileus being "rough with minute granules or squamules," in its closer 

 narrow gills and the absence of odor. It seems to have close affinities with 

 R. pulverulenta. It is not yet with certainty reported for Michigan. The 

 species reported in the lists, in the Report of the Michigan Academy, are 

 probabty R. pulverulenta Pk. 



30. Russula pectinatoides Pk. 



(The pectinata-like Russula.) 



Illustrations: N. Y. Mus. Bull. 116, 1906. PI. 105, fig. 6-10. 



Pileus 3-7 cm. broad, .rather firm becoming fragile, thin, convex, then 

 piano-depressed, viscid when moist, covered by a thin separable pellicle, 

 radiately rugose-striate on the margin, often halfway to the centre, or strongly 

 tubercular-striate, dingy straw^ color, brownish, yellowish-l^rown or umber- 

 brown. Flesh white, thin, becoming fragile, slightly ashy under the cuticle, 

 not changing. Gills whitish, close to subdistant, thin, distinct, equal, 

 moderately broad, broadest in front, narrowed behind, often stained or broken 

 halfway from stem, some forked at base. Stem white or dingy, subequal, 

 glabrous, spongy-stuffed then hollow, even, 2-5 cm. long, .5 to 1 cm. thick. 

 Spores whitish or creamy-white in mass, subglobose, 6-8 micr. diam. Taste 

 mild or slightly and tardily acrid. Odor not noticeable. 



*4th Rep., Mich. Acad, of Sci., p. 120. 



