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

434

North American Species of Lactarius

here we are discounting the difference in the color of the stipe as compared to the type variant and its viscidity. We feel that a large number of observations are needed here before assigning taxonomic importance to the characters.
Still another variant in this group occurs under conifers in the
vicinity of Priest Lake, Idaho (Smith 76733). More data on it are
needed, but we present here that which we have.
Pileus 4-8 cm broad, convex with an inrolled margin, becoming
expanded but with a shallowly depressed disc, dark reddish brown
("Carob-brown") on the disc, margin slightly paler, surface glabrous,
slimy-viscid, azonate to zonate, the inrolled margin at first unpolished.
Context pallid, unchanging, with a strongly acrid taste. Latex milkwhite, unchanging, staining the gills slightly to brown. FeSO4 no reaction on the context.
Lamellae decurrent, cream color to buff when young, more
ochraceous-tan in age, staining brownish slightly, close, narrow, many
of them forked.
Stipe 3-5 cm long, 10-20 mm thick, paler than pileus and with
darker watery spots (scrobiculate), soon hollow, more or less equal,
surface glabrous, viscid, soon dry.
Spore deposit pale warm buff (pale yellow). Spores 6.5-7.5 (8) X
5-6.5 pt, ellipsoid to subglobose, ornamented with a partial reticulum
and some isolated warts, prominences + 0.5 p high.
Basidia 44-50 X 6-10 p, 4-spored. Pleurocystidia: macrocystidia
60-75 X 6-10 pi, fusoid-ventricose to fusoid and acuminate, prominently projecting; pseudocystidia not found. Cheilocystidia + similar
to the macrocystidia but smaller. Pileus trama heteromerous. Pileus
cuticle a thick ixotrichoderm of narrow (2-3,u wide) hyphae, not arising from a cellular layer. Stipe cuticle of narrow, compactly arranged
vertical to interwoven hyphae, a few free ends projecting as caulocystidia, with some slime showing in the layer, possibly with a lax ixoturf
over the glazed spots.
Comments. This variant has the dull colored lamellae of var.
americanus but they stain slightly to a darker brown, the stipe is viscid, and in color a paler brown than the pileus. The forking of the gills
may be a significant additional character.
Material cited.-CALIFORNIA: Smith 8658 (type, MICH), 9441;
IDAHO: Smith 74179, 76733; MICHIGAN: Smith 38733; OREGON:
Smith 27618.
155d. Lactarius hysginus var. subroseus var. nov.
Illus. PI. 121.

Pileus 5-7 cm latus, planus, depressus deinde late infundibuli