The North American species of Pholiota, by Alexander H. Smith and L. R. Hesler.

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The North American Species of Pholiota

Phaeomarasmius erinaceus (Fr.) Kiihner, Encyc. Myc. 7:33. 1935.
Illustrations: Text figs. 31-34; pl. 8b.
Pileus 5-15 mm broad, usually convex, sometimes slightly depressed
on the disc or disc slightly umbonate, surface dry and densely covered
by fibrillose scales, the squamules erect and nearly spine-like over the
disc, toward the margin somewhat appressed, the edge usually fimbriate
with over-hanging fibrils; color medium to dark rusty brown ("auburn"
"russet" or paler and "ochraceous-tawny"), paler and more ochraceous
near the edge. Context thin and fairly tenaceous, pallid brownish, becoming pallid, odor not distinctive, taste not recorded.
Lamellae close to subdistant, broad, bluntly adnate, whitish becoming pinkish-cinnamon or darker.
Stipe 8-15 mm long, 1-2 (2.5) mm thick, equal or base somewhat
enlarged, stuffed by a narrow pith, pliant and tough, lower portion
densely squarrose-scaly with fine fibrillose squamules, somewhat silky
above the fringe left by the broken veil, pallid brownish above, dark
rusty-red below.
Spores 7-10 x 4-5.5 (9-11 x 6-8) F, smooth, relatively thin-walled
(many seen collapsed in mounts in Melzer's reagent) pale dingy ochraceous in KOH, yellowish to pale tawny in Melzer's reagent, broadly ovate
to subrhomboid in face view varying to elliptic, in profile elliptic to
broadly elliptic, some slightly compressed dorsiventrally, apiculus distinct, no apical pore present.
Basidia 1-, 2-, and 4-spored, 18-22 x 7-9,u, hyaline to pale ochraceous
in KOH and Melzer's reagent, narrowly clavate. Pleurocystidia scattered,
30-42 x 7-10 /A, fusoid-ventricose with subacute apex, hyaline, thinwalled, smooth, in some pilei apparently absent. Cheilocystidia 20-35 x
4-9 /u, ventricose at base and with an elongated often crooked and
branched neck ending in a subacute to acute apex, neck portion with
thin hyaline walls but in basal part the walls often yellowish as revived
in KOH. Caulocystidia present as the cystidial to cylindric end-cells of
thick-walled encrusted hyphae, the cells 35-80 x 5-10 Lu diam., also setalike cells present 50-100 x 7-9 /u with an elongated flexuous hyaline
distal half ending in the subacute apex.
Gill trama of subparallel interwoven hyphae with yellow to tawny
walls in KOH but the walls at most only slightly thickened; subhymenium
scarcely differentiated, not gelatinous. Pileus cuticle of fascicles of thickwalled hyplhae the cells tubular to inflated and with walls heavily incrusted, hyphae with end-cells tubular to cystidioid, cells 6-9 /, diam.
when tubular and up to 15 /u when inflated, the subcutis a thin layer of
non-gelatinous brown-walled hyphae appressed-interwoven and with
thinner walls than in hyphae of epicutis. Clamps regularly present. All
tissues inamyloid to weakly dextrinoid.
HABIT, HABITAT, AND DISTRIBUTION: Scattered on twigs of Corylus and
Betula, Northern United States and Canada, not common.