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

Subgenus Plinthogalus

121

Stipe 3-4 cm long, 4-6 mm thick, concolorous with the pileus or
paler especially below, nearly smooth under a lens, solid.
Spore deposit "ochraceous-buff." Spores 7.5-9 t (excl. orn.)
globose to subglobose; plage distinct and diffusely ornamented with
amylaceous material; ornamentation in the form of a partial reticulum
of prominent ridges up to 1.5 ti high.
Basidia 45-52 X 10-12 g, 4-spored. Pleurocystidia: macrocystidia
not observed (none?); pseudocystidia scattered, refractive, filamentous.
Cheilocystidia 22-37 X 3-6 AL, subfilamentous to subfusoid. Gill trama
of hyphae with elongate cells, no rosettes seen; lactifers inconspicuous.
Pileus trama heteromerous, lactifers pallid in KOH; in Melzer's mounts
some large globules present. Pileus cuticle a modified trichoderm,
the lower cells somewhat inflated but not forming a cellular layer,
end cells subcapitate to clavate or subventricose, up to 45, long,
with medium brown intracellular pigment in the end cells and outer
cells of the cuticular zone. Stipe cuticle a turf of caulocystidia 24-45
X 5-8 A,. clavate, cylindric, more or less capitate, brown, arising from a
zone of parallel subcuticular, brown hyphae (no inflated cells present),
the zone adjacent to this layer (to the interior) translucent in KOH; stipe
trama with a few rosettes.
Habit, habitat, and distribution.-In deep moss, in deciduous
woods, Cades Cove, Tennessee, legit L. R. Hesler, No. 29380 (type,
TENN), September 6, 1966.
Observations.-This species is near L. fumosus but distinguished
by darker colors, lack of reddish stains where lamellae are injured,
and the brown caulocystidia.
23. Lactarius subisabellinus Murrill
Lloydia 11: 93, 1948
var. subisabellinus
Lactarius burkei Smith & Hesler, Brittonia 14: 439, 1962.
Illus. Figs. 72, 89, 208.
Pileus 3-6.5 cm broad, convex-depressed, becoming broadly vaseshaped, glabrous, dry, unpolished, under a lens subvelutinous, slightly
rugulose over disc at times, color pale isabelline ("pale pinkish buff"
or slightly darker especially over the disc), drying pallid. Context
pallid, thickish, unchanging when cut; odor none or somewhat fragrant
at first; taste mild. Latex white, copious, unchanging, mild.