North American species of Lactarius / L. R. Hesler, Alexander H. Smith.

Subgenus Tristes

347

Basidia 45-52 X 12-13.5 /u, 4-spored. Pleurocystidia: macrocystidia 67-90 X 9-12 M, fusoid-ventricose, acuminate, or subcylindricmucronate, projecting prominently; pseudocystidia none observed.
Cheilocystidia abundant, 30-60 X 7-9 u, fusoid to aciculate, sharply
pointed. Pileus trama heteromerous, lactifers inconspicuous, some incrustations and debris present in subcuticular region. Pileus cuticle
an ixotrichoderm becoming an ixolattice and finally collapsing and
with the appearance of an ixocutis as revived (on old pilei). Stipe cortex with rosettes; stipe cuticle an ixolattice of narrow ascending hyphae, in places no slime evident.
Habit, habitat, and distribution.-On soil in mixed woods and
along edges of sphagnum bogs, Michigan and Ontario, July-September.
Observations.-In this species the latex is a pinkish buff when
exuded and shows a tendency (in type collection) for the droplets to
dry olivaceous. In Smith 42289 the latex was copious and olive-buff
when exposed. Otherwise the collection appears to be typical of the
species. In aging or in drying cinnamon tones develop and the pileus
may be dull cinnamon in age-very different from the original color. L.
trivia/is has a milk-white latex and an azonate to subzonate pileus,
but changes color much as in L. mackinawensis. The stipe in the
latter may soon become dry, which will cause some difficulty in attempting field identifications, a feature also rather common in L. argillaceifolius.
Material cited. —MICHIGAN: Gilliam 241 (MICH); Patrick
1238 (MICH); Potter 12739 (MICH); Smith 32669 (type, MICH),
32720, 33127, 42289, 57839, 74520, 77930, 78654; N. J. Smith 1472
(MICH).
Canada. ONTARIO: Smith 26464.
123. Lactarius glutinosus Sumstine
Lactaria glutinosa Sumstine, Mycologia 33: 18. 1941 (a variant spelling).
Illus. Fig. 201.
Pileus 4-6 cm broad, convex then depressed in the center,
smoky gray, darker at the center, glabrous, azonate, very viscid in wet
weather, covered with a slime coating which disappears in drying,
margin regular or sometimes sulcate. Context white, thin, taste acrid.
Latex white, unchanging, acrid, not staining the gills.
Lamellae slightly decurrent, white, becoming ochraceous on drying, moderately distant, with shorter ones intermixed.
Stipe 3-4 cm long, 5-15 mm thick, concolorous with or a little