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

The Subgenus Hebeloma

115

Pileus 2-4 cm broad, convex with an incurved margin, expanding
to broadly convex or plane; surface hoary at first from a thin veil, soon
glabrous, subviscid, dingy orange-cinnamon overall and only slightly
duller as dried. Context thickish, pallid brownish; odor and taste
raphanoid; FeSO4 no reaction on pileal context (not recorded for the
stipe base).
Lamellae very broad and ventricose, subdistant to distant, adnate
when young but soon adnexed, pallid, brownish becoming ~ cinnamon, not beaded or spotted.
Stipe ~ 4 cm long, 8-12 mm thick, equal, fragile, pallid above,
cinnamon-buff at the base, apex silky, lower half with zones and
patches from the pinkish buff veil, as dried ~ cinnamon-buff or pinkish
buff overall.
Spores 9-12.5 x 5.5-6.5 plm, appearing smooth in KOH, very
minutely marbled in Melzer's, ellipsoid to ovoid (or some obscurely
bean-shaped in profile view), nearly hyaline in KOH or in Melzer's
singly, pale clay color in groups in KOH.
Hymenium.-Basidia 4-spored, 7-8 Im wide near apex. Pleurocystidia none. Cheilocystidia 40-60 x 6-11 x 5-7 ilm, cylindric or
ventricose near base and the neck elongated to an obtuse to subcapitate apex, hyaline, thin-walled.
Lamellar and pilear tissues.-Lamellar trama typical for the genus. Cuticle of pileus a poorly defined ixocutis, the hyphae 3-6 Ixm
diam. Hypodermium celluar to hyphoid, The hyphal walls rusty brown
in KOH and in Melzer's slightly redder, walls not conspicuously encrusted. Tramal hyphae typical for the genus. Clamps present.
Habit, habitat, and distribution.-Gregarious on sandy soil, Lake
Fork Creek, McCall, Idaho, August 3, 1964 (type, MICH).
Observations.-Rarely one finds a few cheilocystidiumlike cells
on the cuticle of the pileus, but it was not established whether these
originated from veil hyphae or cuticular hyphae. This Hebeloma differs
from H. oregonense in having smaller ellipsoid spores, in the color of
the pileus, and in the apparently nondarkening stipe. It differs from H.
fastibile in having nearly smooth spores under ordinary magnification
as well as in the colored veil.
Stirps KUEHNERI
Spores dextrinoid.
KEY TO SPECIES
1. Pileus corrugated; spores + pointed at both ends............ 61. H. corrugatum
1. Not as above..........................................................2
2. Taste farinaceous; habit typically caespitose......... 62. H. praecaespitosum