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

74

The Veiled Species of Hebeloma

easily removed), hyphae 2-4 [xm diam, hyaline, + refractive, clamps
present. Hypodermium hyphoid, + tawny in KOH, redder in Melzer's,
some dextrinoid debris present.
Habit, habitat, and distribution.-Scattered to gregarious under
spruce, Lizard Head Pass, San Juan County, Colorado, July 27, 1956
(type, MICH).
Observations.-The combination of vinaceous-buff veil (pinkish
gray), and lack of any distinctive odor and taste distinguish this variety
from var. mesophaeum as admitted here, but a close relationship between them is obvious. The most useful difference, in studying herbarium material, is the hyphoid hypodermium but the difference between
cellular and hyphoid can be bothersome. In the course of its development, the layer may be hyphoid first and + cellular at the end point of
development.
35c. Hebeloma mesophaeum var. subobscurum var. nov.
Pileus 3-5 cm latus, obtusus demum planus vel obtuse umbonatus, leviter fibrillosus, glabrescens, rufobrunneus, ad marginem saepe
brunneogriseus. Contextus pallidus; odor et gustus leviter raphanoideus. Lamellae adnexae, "Vinaceous-Buff" juvenis, demum cinnamomeae, confertae, latae. Stipes 4-6 cm longus, 3-8 mm crassus, pallidofibrillosus, deorsum obscurus, aequalis, siccus. Velum fibrillosum,
pallidum, evanescens. Sporae 8-10 (11) x 5-6 pm, + ellipsoideae,
subleves, non dextrinoideae. Cheilocystidia 34-60 x 4-8 ptm, plerumque fusoide ventricosa.
Specimen typicum in Herb. Univ. Mich. conservatum est, Smith
46587; legit prope, Seven-Devils Mts., Riggins, Idaho, 23 Aug 1954.
Pileus 3-5 cm broad, obtuse, expanding to obtusely umbonate to
plane, when young "Benzo Brown" to "Cinnamon Drab" and coated
with a thin layer of fibrils, glabrescent and color then "Verona Brown"
to "Warm Sepia" (reddish to rusty brown), viscid to subviscid, soon
appearing dry. Context pallid, odor and taste slightly raphanoid.
Lamellae adnexed, "Vinaceous-Buff" (grayish pink) when
young, gradually grayer ("Avellaneous"), finally dingy cinnamon from
the spores, close, broad, edges uneven, not agglutinating.
Stipe 4-6 cm long, 3-8 mm thick, pallid from a thin fibrillose
coating, darkening from the base up in age to a sordid brown ("Bister"
or darker), tubular, equal. Veil fibrillose, pallid, thin, evanescent
(scarcely leaving a zone on the stipe.
Spores 8-10 (11) x 5-6 VIm, subelliptic in profile, elliptic in face
view, wall thin, appearing smooth, merely yellowish in KOH, not dextrinoid.