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

168

The Veiled Species of Hebeloma

having a cellular hypodermium. From H. subrimosum it differs in having a raphanoid odor, in the stipe not darkening below, and in the
tendency of the spores to be + inequilateral in profile view.
99. Hebeloma hydrocybeoides sp. nov. (f)
Pileus 2-3.5 cm latus, convexus demum late expansus vel planus,
viscidus nitens laete fulvus demum alutaceus; sapor amarus; odor mitis. Lamellae confertae latae adnatae demum sinuatae, cinnamomeobrunneae. Stipes 2.5-5 cm longus, 2-4.5 mm crassus, aequalis, cavus,
albidus, deorsum tarde brunnescens, leviter fibrillosus; velum sparsum,
evanescens. Sporae 7-9.5 x 5-6 pxm, valde dextrinoideae, rugulosae,
fulvae in "KOH." Cheilocystidia 23-37 x 5-9 VLm vel 36-43 x 4.5-6
[Lm et subfilamentosa. Cuticula pileorum crassa ixocutis est.
Specimen typicum in Herb. Univ. Mich. conservatum est, Smith
36228; legit prope Dixboro, Michigan, 17 Oct 1950.
Pileus 2-3.5 cm broad, convex with the margin inrolled, expanding to plane or nearly so, margin often remaining decurved, surface
glabrous, viscid and shining, "Mars Brown" to "Cinnamon-Brown"
fading to tan. Context brown, taste bitter, odor mild.
Lamellae close, adnexed, finally moderately broad, cinnamonbrown fresh but paler as dried, edges even and not beaded.
Stipe 2.5-5 cm long, 2-4 mm thick, equal, hollow, whitish, fibrillose, a veil absent (young fresh specimens examined) but the fibrils on
the stipe may be indicative of a rudimentary veil; brown in the base
and where the fibrillose coating has been removed, merely pallid
brownish below in herbarium specimens.
Spores 7-9.5 x 5-6 [Lm, russet in KOH, strongly dextrinoid,
distinctly warty-rugulose under high-dry objective; in profile view inequilateral, ovate in face view.
Hymenium.-Basidia 4-spored, 6.5-7.5 pJm wide near apex. Pleurocystidia none. Cheilocystidia fusoid-ventricose to subcylindric, 23-37
x 5-9 pim and fusoid-ventricose, or 36-43 x 4.5-6 x 3-5 tjm and +
filamentous, elongating greatly as aging takes place.
Lamellar and pilear tissues.-Lamellar trama hyaline in KOH,
typical of the genus. Cuticle of pileus an ixocutis to an ixolattice, thick,
hyphae widely spaced, gelatinized in some, 1.5-3 Vtm diam. Hypodermium hyphoid, the area poorly defined. Tramal hyphae typical of the
genus. Clamps present.
Habit, habitat, and distribution.-On soil in a meadow, Dixboro,
Michigan, October 17, 1950 (type, MICH).
Observations.-The color of the spores is that of Cortinarius as is
also the ornamentation. On the fresh material no veil extended from