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

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The North American Species of Pholiota

Hypodendrum aurivelloides Overholts, North Amer. Fl. 10: 281 1932.
Illustrations: Text figs. 214-217.
Pileus 5-8 cm broadly campanulate to convex, ferruginous to tawny,
margin paler, slightly viscid, with a few spot-like or appressed scales.
Context rather thick, yellow.
Lamellae sinuate-adnate or with a decurrent tooth, whitish then
ochraceous-tawny or russet, medium close or slightly distant, broad (7 -12 mm).
Stipe 4-8 cm long, 5-10 mm thick, yellowish or brownish, more or
less scaly, the scales sometimes somewhat gelatinous, equal, solid.
Spores 8-11 (11.5) x 6-7 (8) p,, smooth, wall ~ 0.3 a, thick, apical
pore present and in larger spores often causing spore apex to appear
somewhat truncate, elliptic in face view and also in profile or in profile
varying to slightly bean-shaped, color in KOH yellowish-tawny, more
cinnamon in Melzer's reagent.
Basidia 4-spored, 27-36 x 6-8 up, clavate, hyaline to yellowish in
KOH and in Melzer's reagent. Pleurocystidia abundant, 1) mostly
clavate-mucronate, 25-36 X 8-12 pu, with thin smooth hyaline walls (in
KOH), with a small highly refractive amorphous body not coloring in
Melzer's reagent: 2) obtusely fusoid cells 30-48 x 6-11 /t and with
brownish to ochraceous wrinkled content becoming dark amber-brown
in Melzer's. Cheilocystidia 26-50 x 6-15 ju, versiform; clavate, subelliptic,
inflated-vesiculose and at times capitate, or fusoid-ventricose, yellow to
hyaline in KOH, walls typically thin and content homogeneous or resembling that of either type of pleurocystidia. Caulocystidia scattered,
clavate up to 80 x 22 /., and some with yellow to reddish homogeneous
content in KOH.
Gill trama of floccose parallel hyphae with elongate thin-walled
smooth inflated (finally) cells up to 15 /, diam., hyaline to yellowish in
KOH, and many with highly refractive septa; subhymenium gelatinousnarrow and of interwoven narrow (2 pu) hyaline hyphae. Pileus cutis a
thick gelatinous pellicle of hyphae 3-6 p. diam., walls thin smooth and
hyaline, over this occur patches of amber-brown gelatinous hyphae 4-9 pu
wide (representing the gelatinous scales); hypodermial region not distinct from content. Context hyphae inflated (6-15 / +~), walls thin
smooth, hyaline to yellowish. All hyphae inamyloid. Clamp connections
present.
HABIT, HABITAT, AND DISTRIBUTION: On dead trees or from wounds
in Alnus, Salix or Betula, Colorado, New Mexico, and Wyoming, late
summer and fall. Type studied.
OBSERVATIONS: Our microscopic data in the above description are
taken from Gruber 749, preserved at Michigan. The spores average
broader than for P. aurivella, and there is a distinct difference in the
pleurocystidia as described. Brown imbedded basidioles were not found
in the type by us but were reported by Overlolts, who was an accurate