NATURAL HISTORY SURVEY 55 



Lamellar narrow, close, white or yellowish. 



Stem short, firm, equal or slightly tapering upward, hollow, 

 colored like the pilous, generally spotted. Milk white, taste acrid. 



Spores 7.5 to 9 i*.. Pileus 5 to 10 cm. broad; stem 2.5 to 5 cm. 

 long, N to 16 mm. thick. 



Woods, Millers. August. Harper. 



Lactarius pergamenus Fr. 



White. Pileus fleshy, pliant, convex then piano-depressed, 

 rcpand, slightly wrinkled, smooth. 



Lamellae adnate, very narrow, horizontal, very crowded, 

 branched, white then straw-color; milk white, acrid. 



Stem stuffed, smooth, changing color. 



Pileus 7.5 to 15 cm. broad, stem 3.5 to 7.5 cm. long, lamellae 

 scarcely 2 mm. broad. 



Woods, Glen Ellyn and Winfield. August. Differs from 

 L. piperatus in having the pileus at first convex, the lamellae 

 adnate and narrower, the stem longer and thinner. Spores 

 subglobose, but somewhat irregular, 6 to 8 /m. Gregarious; often 

 three to six plants in a close cluster. The pileus in our plants 

 does not become funnel-shaped but is rimosely incised when fully 

 grown. 



Lactarius piperatus Fr. (Plate VI, Fig. 1.) 



Pileus compact, at first convex and umbilicate, then expanded 

 and centrally depressed or infundibuliform, even, glabrous, white. 



Lamellae narrow, crowded, dichotomous, adnate or decurrent, 

 white or cream-colored. 



Stem equal or slightly tapering downward, solid, glabrous, 

 white. Milk white, abundant, very acrid. 



Pileus 3.5 to 10 cm. broad; stem 2 to 5 cm. long, 10 to 20 mm. 

 thick. Spores white, nearly smooth, 6 to 7.5 /x. 



On the ground in dry or moist woods, Winfield, Glen Ellyn, 

 Glencoe, Highland Park, Riverside. One of our most common 

 species. Specimens 12 cm. broad, with the pileus wholly funnel- 

 shaped are often found. Dr. Watson has collected at Highland 

 Park, a plant which may be this species, but so distorted by 

 Hypomyces lactifluorurn as to be unrecognizable. The spores 

 upon the specimens are wholly those of the parasite. Similar 

 specimens have been collected at River Forest by Wyrick, and at 

 Winfield by the writer. 



Lactarius Indigo Schw. 



Pileus at first umbilicate with the margin involute, then de- 

 pressed or infundibuliform, indigo-blue with a silvery-gray luster, 

 zonate, especially on the margin, sometimes spotted, becoming 

 paler and less distinctly zonate with age. 



Lamellae close, indigo-blue, becoming yellowish and some- 

 times greenish with age. 



Stem short, nearly equal, hollow, often spotted with blue, 

 colored like the pileus. Milk dark blue. 



