The veiled species of Hebeloma in the western United States / Alexander H. Smith, Vera Stucky Evenson, and Duane H. Mitchel.

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The Veiled Species of Hebeloma

Pileus 1-2.5 cm broad, obtuse to convex and with margin incurved, expanding to campanulate to plano-umbonate, margin at first
faintly fibrillose from veil fibrils, soon glabrous overall, viscid; color
"Sayal Brown" (dull cinnamon) to the "Cinnamon-Buff" margin
(slightly paler than the disc). Context thin, brownish, odor and taste
mild.
Lamellae broad, close adnate, pallid then brownish and finally +
"Sayal Brown," edges even and neither beaded nor spotted.
Stipe 2-4 cm long, 2.5-3.5 mm thick, equal, faintly fibrillose
from the thin veil but no annular zone (veil-line) present (just a few
patches or a partial zone present), becoming dark brown over the
lower portion, pallid and silky above.
Spores 7-9 x 4-5.5 VLm, roughened, dingy pale buff in KOH, +
dextrinoid; shape in profile view distinctly inequilateral, in face view
ovate.
Hymenium.-Basidia 4-spored, 6.5-8 Ipm broad. Pleurocystidia
none. Cheilocystidia small, (18) 22-27 x 4-7 pxm, filamentous to narrowly clavate (possibly elongating somewhat), hyaline, thin-walled and
difficult to revive.
Lamellar and pilear tissues.-Lamellar trama typical for the genus. Cuticle of pileus an ixotrichodermium collapsing to an ixolattice,
the hyphae + 1.5 pm diam, refractive, sparsely branched, clamped.
Hypodermium hyphoid, rusty brown in KOH, bay-red in Melzer's,
walls not heavily encrusted. Tramal hyphae typical of the genus.
Clamps present.
Habit, habitat, and distribution.-On soil along a trail, Storm
King Mt., Olympic National Park, Washington, October 16, 1941
(type, MICH).
Observations.-The hyphoid hypodermium and the distinct ixotrichodermium, the short cheilocystidia and small dextrinoid spores are
the important microscopic features. The field characters are somewhat
routine: lack of an odor and taste, the stipe darkening at the base, and
the pale cinnamon pileus.
50. Hebeloma pinetorum sp. nov.
Pileus 1-2.5 (3) cm latus, demum campanulatus vel planoumbonatus, sparsim fibrillosus, glabrescens, glutinosus, pallide argillaceus; odor fragrans. Lamellae angustae, confertae, adnatae, luteobrunneae. Stipes 2-3.5 cm longus, 2.5-3 mm latus, tenuiter fibrillosus,
glabrescens, deorsum brunnescens. Sporae 9-11 x 6-7 JIm, subleves in
"KOH," dextrinoideae, inequilaterales. Cheilocystidia 27-41 x 8-11