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

margin remaining coated with veil remnants for some time, as dried
about "Army Brown" overall; odor and taste distinctly raphanoid.
Lamellae broad, close, adnate, pallid when young, rusty cinnamon at maturity, not beaded or spotted.
Stipe short (2-3 cm long), 3-4 mm thick, silky, pallid and with
only a faint veil-line and this soon evanescent, brunnescent and darkening from below upward, as dried brownish pallid overall.
Spores 10-13 (14.5) x 6.5-7.5 pm, apparently smooth under
high-dry objective but in Melzer's under an oil-immersion lens faintly
mottled; clay color in KOH, dextrinoid, in profile + inequilateral, in
face view ovate.
Hymenium.-Basidia 4-spored, 9-12 (Lm wide. Pleurocystidia
none. Cheilocystidia (37) 48-70 x 5-10 x 4-6 (16) fim; some elongated
and cylindric, or walls flexuous, some narrowly fusoid-ventricose, some
+ elongate-clavate, all types hyaline in KOH.
Lamellar and pilear tissues.-Lamellar trama typical for the genus. Cuticle of pileus an ixolattice, the hyphae 2-4 (5) pxm diam,
hyaline to yellowish in KOH. Hypodermium the intermediate type,
reddish rusty in KOH and with conspicuous colored incrustations, the
layer bay-red in Melzer's. Tramal hyphae of pileus flushed red in
Melzer's but soon fading. Clamps present.
Habit, habitat, and distribution.-Under alder, South Fork, Lake
Fork Creek, McCall, Idaho, September 10, 1956; Smith 53299; Colorado, Smith 87552, 88911.
Observations.-On the basis of the top-heavy appearance of the
basidiocarps, the dark-colored pilei, the large and + inequilateral
spores, the long cheilocystidia with flexuous walls and the poorly developed ixocutis of the pileus, we assign our collections to H. marginatulum. Bruchet's figures 1-2 express the aspect of the North American fruiting bodies very well. Apparently this is a very rare species in
North America.
72a. Hebeloma marginatulum var. fallax var. nov.
Illus. Figs. 45-46.
Pileus 2.5-4 cm latus, plano-convexus, ad marginem griseobrunneus, sparsim fibrillosus, ad centrum obscure vinaceobrunneus, glabrescens. Contextus brunneolus demum pallidus, odor et sapor raphaninus. Lamellae adnatae, latae, demum subdistantes, brunneolae
demum obscure cinnamomeae. Stipes 3-7 cm longus, (2) 3-5 mm
crassus, dissiliens, deorsum brunneolus. Velum sparsim, pallidum vel
cinereum. Sporae 10-15 x 6.5-8,xm, inequilaterales, pallide cinnamo