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

66

The Veiled Species of Hebeloma

profile subelliptic, thin-walled, not dextrinoid, appearing smooth or
under oil + rugulose, merely yellowish in KOH.
Hymenium.-Basidia 4-spored, 17-25 x 6-12 JIm. Pleurocystidia
none. Cheilocystidia 40-80 x 6-12 pxm, elongate fusoid-ventricose,
apex obtuse to slightly enlarged, slightly ochraceous in the ventricose
part.
Lamellar and pilear tissues.-Lamellar trama typical for the genus. Cuticle of the pileus a well-developed ixolattice of slender (2-3
xLm diam) tubular hyphae. Hypodermium cellular, cell walls heavily
incrusted, dark yellowish brown in KOH. Pileus trama compactly interwoven, the hyphae 5-9 txm diam, pallid ochraceous to hyaline in
KOH. Clamps present.
Habit, habitat, and distribution.-Scattered under lodgepole pine,
spruce, and fir, Fryingpan River above Elk Wallow, Pitkin County,
Colorado, August 19, 1978 (type, MICH).
Observations.-The relatively narrow spores, grayish-buff copious veil, and the walls of the hypodermial cells heavily encrusted as
mounted in KOH, are distinctive. H. glabrescens when fresh and moist
has the colors of H. mesophaeum var. holophaeum Fries, but to properly settle the question of their identity a neotype must be selected for
the Friesian variety. We cannot do this on the basis of North American
specimens.
32. Hebeloma subviolaceum sp. nov.
Illus. Figs. 13-14.
Pileus 2.5-4 cm latus, late convexus demum ~ planus, subviscidus, canescens, griseobrunneus demum rubrobrunneus vel atrobrunneus, squamulosus, glabrescens. Velum albidum. Odor and gustus mitis. Lamellae latae, confertae, adnatae, "Vinaceous-Buff" demum
"Verona Brown," Stipes 3-5 cm longus, 4-6 mm crassus, fragilis,
brunnescens, deorsum fibrillosus, subannulatus. Sporae 7-10 x 5-6
pm, subleves, ellipsoideae vel ovoideae, apice rotundatae, rare obscure inequilaterales. Cheilocystidia 26-35 x 10-15 jim, saccata vel
ellipsoidea vel fusoid-ventricosa et 38-57 x 7-10 x 4-5 VLm, tarde
agglutinata.
Specimen typicum in Herb. Univ. Mich. conservatum est, Smith
88843; legit prope Elk Camp, Burnt Mt., Pitkin County, Colorado, 2
Aug 1978.
Pileus 2.5-4 cm broad, broadly obtuse becoming broadly convex
or the margin uplifted; subviscid; color ~ "Benzo Brown" beneath the
veil fibrils, in age a dark "Verona Brown" to "Dresden Brown" or