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

Subgenus Lactifluus

177

(gray-brown), stains remaining localized, taste mild or finally faintly
peppery.
Lamellae pale yellow ("pale ochraceous-buff" to "light ochraceous-buff"), near maturity "pinkish buff" or orange-buff and stained as
indicated above, distant, becoming decurrent, broad, not forked.
Stipe 3-7 cm long, 9-16 mm thick, narrowed downward, dry, dull,
paler than pileus, where handled slowly staining like the lamellae.
Spore deposit creamy white to "pale pinkish buff." Spores 7-9.4
X 6-7.5 Iu (from deposits), broadly ellipsoid, plage distinct and many
showing a small diffusely amyloid spot in the center; ornamentation of
isolated particles and low bands or ridges at times united enough to
form a broken reticulum, prominences 0.2-0.5 pt high.
Basidia 51-54 X 9-11 A, 4-spored. Pleurocystidia: neither
macrocystidia nor pseudocystidia observed (young and old material
examined). Cheilocystidia scarcely differentiated (see fig. 41). Gill
trama heteromerous, lactiferous hyphae inconspicuous. Pileus trama
heteromerous, lactifers inconspicuous, oily globules abundant in
mounts. Pileus cuticle a distinct cellular layer, the cells inflated to
26 I at times, and giving rise at surface of layer to a turf of acute to
blunt pileocystidia with flexuous thickened walls, 40-150 X 2-3 u,
the walls often with amorphous adhesions. Stipe cortex with rosettes.
Stipe cuticle finally a well-developed + cellular layer in age, the
cells not greatly inflated (5-12 Ai), and giving rise to an epicuticular
dry turf similar to that of the pileus and its elements also with adhesions, some elements up to 50,a long or more.
Habit, habitat, and distribution.-Gregarious on low wet soil,
summer and early fall, Michigan and Tennessee. Smith 84285 (type,
MICH) is from a single large fruiting.
Observations.-This is the common variant of L. hygrophoroides
in the western Great Lakes area. As defined at present it is variable in
a number of characters. The problem is one of getting reasonably
complete data on the collections to allow meaningful comparisons to
be made. As indicated, this variety differs from var. hygrophoroides
in having a yellowish spore deposit, but here problems are encountered
since in a thin to moderately heavy deposit the spores appear white.
In some of Hesler's collections (see 25647) the lamellae stained lavender and a white spore deposit was obtained. Smith 85577 from Oakland
County, Michigan, stained pinkish (not going to brown) and the deposit was creamy white. In other collections the stains changed finally
to brown. We believe it is justified to emphasize the vinaceous stains
on bruised gills because of the situation in subgenus Plinthogalus
where they are characteristic, and both subgenera are related by other
characters. In both subgenera the change may progress to brown or it
may not.