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

Subgenus Piperites

221

Observations.-This species is very close to L. necator but has
larger spores with longer ornamentation as well as an intensely acrid
taste. In Smith 83161 from Idaho the latex changed to dark olive on
the gills in a few minutes. The basidiocarps dry olive-fuscous much
as those of L. necator.
Material cited.-IDAHO: Smith 82750, 83161; OREGON: Smith
24035, 27726, 79215, 80084; WASHINGTON: Smith 16731, 29911,
30192, 30375, 30711, 31019 (type, MICH), 47917, 48990, 49135, 49157,
82083.
58. Lactarius atroviridis Peck
Ann. Rep. N.Y. State Mus. 42: 23. 1889
Lactarius sordidus var. hirsutus Pk., Ann. Rep. N.Y. State Mus. 32: 56. 1879
Illus. Pls. 83-84; figs. 82-83, 86.
Pileus 6-15 cm broad, convex, soon plane and depressed, pale to dark
olive-green ("vetiver green," "andover green," or "dark ivy green"),
usually with darker olive spots arranged concentrically, surface is
squamulose to scabrous-fibrillose to nearly glabrous especially on the
disc, dry, in age becoming more or less rimose-areolate, margin involute, at times radiately ridged. Context whitish to pale pinkish buff,
compact, thick on the disc, thin on the margin; odor slight, taste acrid.
Latex white, unchanging or slowly dull olivaceous, staining the lamellae
olive-gray to greenish, acrid.
Lamellae adnate to short-decurrent, whitish to pinkish buff, becoming spotted greenish to brownish, edges often staining greenish,
sometimes forking near the stipe, close, narrow then becoming broad
in age, lamellulae numerous.
Stipe 2-8 cm long, 10-20(30) mm thick, concolorous or paler,
usually spotted darker greenish with polished spots (scrobiculate),
dry, glabrous, soon hollow.
Spore deposit pale cream color (yellowish). Spores 7-9 X 5.5-6.5,t (from deposits); ellipsoid to broadly ellipsoid; with a distinct plage,
lacking a diffusely amyloid patch on it; ornamentation in the form of a
broken to partial reticulum with some free-ending branches, isolated
particles and warts also present, the prominences 0.2-0.5 A, high.
Basidia 34-45 X 7-9,u, 2- and 4-spored. Pleurocystidia: macrocystidia varying from apparently absent to abundant, (38)45-60(120)
X 6-12 ui, clavate to fusoid and pointed, often conic apically; pseudocystidia present, filamentous and embedded in the hymenium. Cheilocystidia 27-40 X 4-9,u, similar to macrocystidia, not abundant. Gill