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

closely related to the species of subgenus Hebeloma. It is distinguished
as a species by the pileal ixotrichodermium, dextrinoid spores, weak
FeSO4 stain on the base of the stipe, mild taste, and vinaceous-brown
pilei. In Smith 87013 hyaline droplets were present on the gills.
74. Hebeloma kuehneri Bruchet
Bull. Soc. Linn. de Lyon, 39 annee: 21. Jun 1970
Illus. Bruchet, l.c., pl. ii.
Pileus 2.5-4 cm broad, obtuse to convex, becoming planoumbonate or broadly campanulate, subviscid, "Prout's Brown" (dark
date brown) beneath a faint hoary coating of whitish fibrils, margin
fringed at first, color finally pallid on the margin, the disc about "Wood
Brown," opaque at all times. Context watery brown fading to pallid,
odor pungent, taste slight; FeSO4 staining base of stipe olive-fuscous.
Lamellae broad, close, adnate, dull pinkish brown ("Pinkish Cinnamon") at maturity, edges serrulate, not beaded and not spotted.
Stipe 2-4 cm long, 3-5 mm thick, equal, hollow, brownish
within, surface whitish at first, pruinose above, darkening from the
base up; veil remnants very inconspicuous.
Spores 10-14 x 6.5-8 pJm, shape in profile + inequilateral, in
face view ovate to broadly fusiform, ~ clay color in KOH, slowly but
distinctly dextrinoid, surface marbled to faintly rugulose, apex obtuse.
Hymenium.-Basidia 4-spored, 8-11,xm broad near apex. Pleurocystidia none. Cheilocystidia fusoid-ventricose, 34-55 (62) x 7-12 x
3-5 Jim, apex obtuse, no secondary septa observed, only one cystidium seen forked at apex.
Lamellar and pilear tissues.-Lamellar trama typical for the genus. Cuticle of pileus a poorly defined ixocutis of hyphae 2-3.5 JIm
diam, clamped and often with faintly roughened walls, the layer intergrading with the hypodermium. Hypodermium mostly hyphoid, the
hyphal walls dark rusty brown and heavily encrusted (as revived in
KOH), a redder brown in Melzer's, dextrinoid debris rather abundant
in and near the layer. Tramal hyphae typical of the genus and not
having red content in mounts in Melzer's. Clamp connections present.
Habit, habitat, and distribution.-Gregarious on duff, Independence Pass area, Pitkin County, Colorado, August 14, 1978, Smith
88982 (MICH).
Observations.-This species is recognized by the very thin pallid
veil, broad lamellae and dark brown pileus. It is difficult to recognize
in the field. Both alder and conifers were present in the North American habitats where it was found.