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

wash of a stream, Elk Camp, Burnt Mt., Pitkin County, Colorado,
July 14, 1979 (type, MICH).
Observations.-The diagnostic features of this species are: (1) the
poorly defined ixocutis; (2) the copious pallid veil; (3) the shape of the
spores and the fact that they are practically smooth and are not dextrinoid; (4) the agglutinating cheilocystidia as described; (5) the narrow
gills, and these grayish when young; and (6) the darkening stipe. It
fruited in great abundance in the type locality and the basidiocarps
were found to retain their features for periods of up to ten days. Smith
89471 is designated as the type because of the more detailed information available on it. The collection 6235 made by Solheim was from
Nash Fork Campground, Albany County, Wyoming at + 10,000 ft.
elevation.
35. Hebeloma mesophaeum (Fr.) Quelet
Champ. Jura et Vosges p. 128. 1872
var. mesophaeum
Pileus 2.5-6 cm broad, at first convex to campanulate, or subumbonate to ~ conic, finally expanding to plane or broadly umbonate, at
times the central area depressed, viscid, margin grayish brown to near
clay color or pinkish buff but the disc usually darker and dull vinaceousbrown (near "Rood's Brown" to "Warm Sepia"), often hoary and with
white patches of veil material near the margin or midway to the disc.
Context white, thick on the disc, rather thin on margin; odor and taste
of radish to not distinctive.
Lamellae broad, narrowly adnate to adnexed or emarginate, at
first whitish, finally "Cinnamon-Buff" to "Sayal Brown," close, broad,
3-4 ranks of lamellulae; edges white floccose but not beaded.
Stipe 3-7 cm long, 3-8 mm thick, dingy brownish, darker below
especially in age, mealy and pallid near apex, fibrillose-striate below,
equal or nearly so; veil white to pallid, fibrillose, typically leaving
remnants on or near pileus margin and/or on the stipe, an annular zone
often present.
Spore deposit "Dresden Brown" fresh, near "Sayal Brown" as
air-dried. Spores 8-10.5 (11) x 5-6 [tm, in profile obscurely inequilateral, in face view elliptic to broadly ovate, walls about 0.3 pxm thick,
minutely marbled under a high-dry lens, pale ochraceous in KOH, not
dextrinoid.
Hymenium.-Basidia 4-spored, 24-34 (40) x 7-9 (Im. Pleurocystidia none. Cheilocystidia 30-54 (70) x 5-12 x 3-5 Vum, subcylindric