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

The Subgenus Hebeloma

131

meae (cum "KOH"), dextrinoideae, subleves. Basidia tetraspora.
Pleurocystidia nulla. Cheilocystidia conspicua, cylindrica, vel ventricosa ad basin, elongata, 40-90 x 5-8 x 3-5 Jim.
Specimen typicum in Herb. Univ. Mich. conservatum est, Smith
89724; legit prope Snowmass Village, Pitkin County, Colorado, 12
Aug 1979.
Pileus 2.5-4 cm broad, plano-convex, the margin dull grayish
brown and thinly coated with grayish buff fibrils from the veil, disc dull
reddish brown and dried evenly + "Army Brown" (vinaceous-brown)
overall, glabrescent. Context with a raphanoid odor and taste, brownish fading to pallid, FeSO4 staining stipe base olive.
Lamellae broad, close to subdistant, adnate, pallid dull brown
becoming wood brown and finally dull cinnamon ("Sayal Brown"), not
beaded.
Stipe 3-7 cm long, (2) 3-5 mm thick, equal to slightly enlarged
below, pallid and thinly fibrillose, as dried evenly brownish overall,
changing to brown from the base upward when fresh, very fragile and
readily splitting lengthwise. Veil cortinate and thin, remains + evenly
dispersed, buff colored where in distinct patches.
Spore deposit (on stipes) dull cinnamon. Spores 10-15 x 6.5-8
Eim, ovate in face view, inequilateral in profile, pale cinnamon as
revived in KOH, dextrinoid, appearing smooth in outline, with a large
central globule as seen mounted in KOH.
Hymenium.-Basidia 4-spored. Pleurocystidia none. Cheilocystidia conspicuous, cylindric to ventricose-elongate, 40-90 x 5-8 x 3 -5 jim, basal area in some with a pale brown homogeneous content
(or color located in the wall?) not becoming agglutinated as far as
observed.
Lamellar and pilear tissues.-Lamellar trama with a slight rosered reaction as mounted in Melzer's but soon fading and the hymenium ~ ochraceous or orange-ochraceous. Cuticle of pileus a poorly
defined ixocutis. Hypodermium of loosely interwoven hyphae 12-20
Jim diam, cells short to long, in Melzer's the heavy incrustations highly
pigmented (bay-red), in KOH duller but nevertheless colored. Clamps
present. Tramal hyphae flushed red in Melzer's but quickly fading.
Habit, habitat, and distribution.-Gregarious on humus under
brush and aspen with conifers nearby; near Snowmass Village, Pitkin
County, Colorado, August 12, 1979 (type, MICH).
Observations.-The pale cinnamon color of the spores in KOH,
the loosely organized hypodermium, the buff cortina and in this variety
in particular, the raphanoid odor and taste, are critical characters. The
cheilocystidia in some KOH mounts showed interior apical thickenings
which dissolved in KOH in approximately 20 minutes.