206 NORTH AMERICAN FLORA [VoLUME 9 
3. Russula nigricans (Bull.) Fries, Syst. Myc. 1: 60. 1821. 
Agaricus nigricans Bull. Herb. Fr. #1. 212. 1784. 
Agaricus nigrescens Krombh. Abbild. 9:27. 1845. 
Pileus convex and umbilicate, expanding and centrally depressed, 7-13 cm. broad; surface 
pure-white or stained with smoky-brown, becoming blackish or dark-fuliginous, slightly 
viscid when wet, glabrous; margin incurved at first, even: context firm, white, slowly changing 
to reddish where wounded and becoming black, mild to the taste, without odor; lamellae 
white, becoming blackish with age or in drying, unequal, slightly rounded at the inner ends 
and adnexed, broad, subdistant; stipe white, becoming smoky-brown with age, solid, 6 cm. 
long, reaching 3 cm. thick: spores white, broadly elliptic, very finely echinulate, 7 X 8.7 u. 
‘TYPE LOCALITY: France. é 
Hasirar: On the ground in coniferous or mixed woods, in rather dry soil. 
: eee Maine to Virginia and North Carolina and west to Wisconsin and Oregon; also 
in Europe. 
ILLUSTRATIONS: Barla, Champ. Nice pl. 17, f. 1-9 (as Agaricus adustus Pers.); Bull. Herb. Fr. 
pl. 212, 579, f. 2; Cooke, Brit. Fungi pl. 1015; Gill. Champ. Fr. pl. 625: Hussey, Ill. Brit. Myc. 1: 
pl. 73 (as Agaricus adustus); Krombh. Abbild. pl. 70, f. 14, 15; Quél. Champ. Jura Vosg. pl. 12, f. 1; 
Richon & Roze, Atl. Champ: #1. 41, f. 19-22; Ricken, Blatterp. Deutschl. gl. 15, f. 2; Lanzi, Funghi 
Mang. Pl. 51, f. 2, a, b, c; Sow. Engl. Fungi pl. 36 (as Agaricus elephantinus). 
4. Russula densifolia (Secr.) Gill. Champ. Fr. 231. 1876. 
Agaricus adustus densifolius Secr. Mycogr. Suisse 1: 476. 1833. 
Pileus fleshy, firm, convex, then depressed, up to 10 cm. broad; surface white, then 
fuliginous, gray, or smoky-brown, viscid when wet, glabrous; margin even, inflexed for some 
time: context white, then reddish where wounded and at length black, mild, without special 
odor; lamellae white, reddish, then black where wounded, unequal, some forking, adnate to 
decurrent, close; stipe white, then sordid to gray, at length blackening, firm, slightly pruinose, 
4 cm. long, up to 2.5 em. thick: spores white, globose, 7—8 u in diameter. 
TYPE LOCALITY: France. 
Hasitat: On the ground in mixed woods. 
DISTRIBUTION: Vermont to the District of Columbia and west to Michigan; also in Europe. 
ILLustRatTions: Cooke, Brit. Fungi pl. 1017; Gill. Champ. Fr. pl. 173 (608); Rep. Mich. Acad. 
Sci. 11: f. 1; Lucand, Champ. Fr. $l. 43; Pat. Tab. Fung. f. 200, 319. 
5. Russula sordida Peck, Bull. Buffalo Soc. Nat. Sci. 1:57. 1873. 
Pileus convex, becoming centrally depressed, 7.5-15 cm. broad; surface sordid-white, 
becoming smoky-brown with age, dry, glabrous, margin even: context white, changing to 
blackish-brown or bluish-black where cut or bruised, mild or tardily acrid; lamellae white, 
changing to blackish-brown or black with age or in drying, unequal, sometimes forked, adnate 
to slightly decurrent, close; stipe white, becoming smoky-brown with age or where wounded, 
equal, solid, firm, 2.5-5 cm. long, 1.2-2.5 cm. thick: spores white, globose, very minutely 
echinulate, appearing nearly smooth, 8 » in diameter. 
Type LOCALITY: Worcester, New York. 
Hasrrat: On the ground under hemlocks. 
DISTRIBUTION: Maine, Connecticut, New York, Ohio, and Missouri. 
Innusrrations: Bull. N. Y. State Mus. 105: pl. 98, f. 1-5. 
6. Russula subsordida Peck, Bull. N. Y. State Mus. 105: 40. 1906. 
Pileus firm, convex, becoming nearly plane or centrally depressed, up to 13 cm. broad; 
surface white, becoming smoky-brown with age, sometimes with an olive-green tint, viscid 
when young or wet, glabrous; margin even: context grayish-white, slowly changing to smoky- 
brown when cut or broken, mild or slightly and tardily acrid; lamellae whitish, becoming black 
or blackish with age or in drying, unequal, adnate, thin, close; stipe white, becoming smoky- 
brown with age or where wounded, solid, becoming spongy within and sometimes hollow, 
glabrous, 2.5-3.5 cm. long, 1.2-2.5 cm. thick: spores white, globose, with scattered, blunt 
papillae on the surface, 8 » in diameter. 
TYPE LocaLity: Horicon, Wayne County, New York. 
Hastrrat: In deciduous or mixed woods. 
DISTRIBUTION: New England to Alabama and west to Ohio. 
ILLUSTRATIONS: Bull. N. Y. State Mus. 105: 1. 99, f. 1-5. 
