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

The Subgenus Hebeloma

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to elongate fusoid-ventricose, hyaline, wall in neck often flexuous,
often with a crook (knee-joint-like) near the base.
Lamellar and pilear tissues.-Lamellar trama typical for the genus
(lacking red tints in Melzer's). Cuticle of the pileus a well-developed
ixocutis to an ixolattice; hyphae clamped, the walls refractive and the
hyphae 1.5-4 Im diam. Hypodermium cellular, the walls dark brown
in KOH. Tramal hyphae of the pileus lacking a red reaction with
Melzer's.
Habit, habitat, and distribution.-Solitary to gregarious or
clustered on soil under conifers, especially spruce, late fall, summer,
and early spring. It is widely distributed throughout the western
United States. A typical specimen is Smith 49417.
Observations.-This is still a collective species as described here
for North American material. There is little likelihood of clearing up
the problems of its variation in Europe until a type collection consistent with the protologue of the species is established for it. The
problems rest mainly with variation in a number of characters important in the subgenus. The spores are borderline between the beanshaped and inequilateral types. We as yet do not have much data on
the iodine reactions of the spores and tissues of the basidiocarp on
European material, and the same is true for the color of the veil and
the changes it undergoes as the stipe tissues become discolored.
Nearly all of the following varieties were carried as "species" in our
preliminary manuscripts.
Bruchet's (1970) account covers our "typical" material rather
well. The important combination of characters as we have found it for
North American collections is as follows: Either the taste or odor is
raphanoid to some extent, and the taste soon becomes bitterish in most
collections, the pileus is dark brown when moist, and the stipe darkens
at the base and the change progresses upward, the veil is white, the
spores are 8-10 (11) x 5-6 VJm and not truly inequilateral but ~
bean-shaped in profile view. Many cheilocystidia are ventricose at or
near the base, and in optical sections the wall of the neck is seen to be
wavy to irregular. Finally, the apex of the cheilocystidium typically is
subacute to obtuse (not significantly enlarged).
KEY TO VARIANTS
1. Pileus lateritius; stipes 7-10 mm thick...................... 35a. var. lateritium
1. Not with above combination of features.................................... 2
2. Lam ellae pinkish gray at first......................................... 3
2. Lamellae when young not as above.................................... 4
3. Veil pinkish gray................................ 35b. var. velovinaceum
3. Veil pallid (see 34. H. solheimii also)............... 35c. var. subobscurum
4. O dor and/or taste raphanoid.......................................... 5
4. N ot as above........................................................ 6