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

The Subgenus Hebeloma

141

Description from Hesler and Smith manuscript
Pileus 3-6 cm broad, convex or nearly plane, yellowish ochraceous or alutaceous whitish or slightly tawny, wavy, obtuse, glabrous,
viscid, margin even, pubescent and incurved. Context white; odor
raphanoid, taste bitter.
Lamellae broad, subdistant, sinuate to adnexed or emarginate,
unequal, pallid, finally becoming cinnamon, edges white-fimbriate, at
times beaded with watery drops.
Stipe 4-6 cm long, 5-10 mm thick, white, firm, fibrillose, equal
above the bulbous base, solid or slightly hollowed. Veil webby, leaving
remnants on upper portion of stipe; sometimes forming a ring.
Spores (9) 10-12 x 5.5-6.5 jIm, slightly inequilateral in profile,
elliptic in face view, minutely rugulose, with a slight "nose" in some,
pale yellowish brown in KOH. Pleurocystidia none. Cheilocystidia 36 -78 x 5-9 (12) Jim, ampullaceous with a neck, noncapitate or slightly
so, some of them narrowly clavate, agglutinating finally.
Pileus cuticle an ixocutis. Pileus trama of radially disposed hyphae.
Hypodermium hyphoid. Stipe cuticle of dry, repent hyphae. Caulocystidia occurring in scattered tufts and similar to the cheilocystidia.
Observations.-Although H. fastibile occurs in North America, it
has been infrequently reported (see Peck [1910] and Kauffman [1918]).
It was described by Persoon, and collections are on deposit at Leiden.
These have been studied microscopically by both Singer (1961) and
Horak (1968). Singer states that the Persoon and the Fries descriptions
agree, and that at Leiden there are two Persoonian collections: Nos. L
910. 258-951 and L. 910. 258-593. In the absence of a designated
holotype, Singer has selected the latter of the two collections to serve
as the lectotype. Despite slight differences in spore size of the two
collections, he is of the opinion that both are eligible to serve as the
lectotype. The label on the one he selected bears the notation "cum
cortina." It was found by Singer to have spores 8.5-10 x 4.5-5.7 jim,
melleous, practically smooth, and ellipsoid to fusoid-ellipsoid. He further stated that he was unable to find cheilocystidia (later observed by
Horak). In the other Persoon collection, the spores measure 10.2-12
x 5.8-7 Jim.
Horak (1968) in his study of the lectotype, gives a full description
not only of the microscopic characters observed, but also of macroscopic features. He found spores to be 8-10.5 x 4.5-6 Jm, with the
wall rugulose, and in shape ellipsoid to almond-shaped. He found
cheilocystidia 40-65 x 7-9 jxm which were ampullaceous and not capitate or only obscurely so.
Pomerleau (1980) reports H. fastibile from Quebec. H. colora