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

sapor mitis. Lamellae angustae, subdistantes, pallide avellaneae demum
rufobrunneae. Stipes 2-3 cm longus, 3-4 mm crassus, deorsum fuscobrunneus, sursum pallidus, sericeus. Velum pallidum tenuiter fibrillosum. Sporae 9-11.5 x 6-6.5 jxm, dextrinoideae, inequilaterales. Cheilocystidia 36-65 (74) x 5-12 x 4-6 Jim, subcylindrica vel ad basin +
ventricosa. Cuticula pileorum ixolattice est. Hypodermium cellulosum.
Specimen typicum in Herb. Univ. Mich. conservatum est, Smith
89110; legit prope Savage Lakes, Pitkin County, Colorado, 23 Aug
1978.
Pileus 1-2.5 cm broad, convex to plano-convex or umbonate,
surface glabrous, slimy-viscid when fresh, disc dark tawny, margin
pinkish buff or paler, pale pinkish buff overall when faded; odor
slightly pungent, taste mild; FeSO4 olive-fuscous on lower part of stipe.
Lamellae narrow, subdistant, adnate, pallid, avellaneous becoming reddish brown, neither beaded nor spotted.
Stipe 2-3 cm long, 3-4 mm thick, equal, soon dark brown at the
base, pallid and silky at apex; veil remnants present as a few indistinct
zones on lower half of stipe.
Spores 9-11.5 x 6-6.5 Jim, in KOH dull clay color, in Melzer's
weakly dextrinoid to tawny-red, surface obscurely mottled (under a
high-dry objective), shape in profile inequilateral, in face view ovate,
the apex blunt.
Hymenium.-Basidia 4-spored, 7-10 jim wide near apex. Pleurocystidia none. Cheilocystidia 36-65 (74) x 5-12 x 4-6 iLm, cylindric
down to a ventricose base, the neck finally greatly elongated, secondary septa in neck rare; none forked at apex.
Lamellar and pilear tissues.-Lamellar trama typical of the genus
except for the hymenium and subhymenium, becoming reddish orange
in Melzer's. Cuticle of pileus a thick ixolattice of hyphae 2-4 jim diam,
embedded in a slime matrix, walls refractive, dextrinoid debris moderately abundant in the layer, clamp connections present. Hypodermium
a cellular layer (in tangential sections), intermediate as seen in radial
sections, with patches of encrusting pigmented material on the cell
walls or as wall thickenings, the walls and incrustations rusty brown in
KOH, "Mars Orange" in Melzer's. Tramal hyphae typical of the genus
(not red or orange in Melzer's).
Habit, habitat, and distribution.-On muck in a mixed conifer
forest (pine and spruce), Savage Lakes area, Pitkin County, Colorado,
August 23, 1978 (type, MICH).
Observations.-The slimy pileus when fresh, the narrow gills, the
medium-sized spores, and lack of a distinctive odor and taste characterize this species.