The North American Species of Pholiota

58. Pholiota albocrenulata (Pk.) Saccardo, Syll. Fung. 5: 760. 1887.

Agaricus albocrenulatus Peck, Buffalo Soc. Nat. Sci. 1: 49. 1873.
Hypodendrum albocrenulatum (Pk.) Overholts, North Amer. Flora 10: 281. 1932.
Hebeloma albocrenulata (Pk.) Singer, Rev. de Mycol. 4: 72. 1939.
Stropharia albocrenulata (Pk.) Kreisel, Fedes Repertorium 3: 212. 1964.
Pholiota fusca Quélet, Champ. Jura & Vosges 4th Suppl. 1876.

Illustrations: Text figs. 59-61; pls. 25c, 26, 27.

Pileus (2.5) 3-8 (12) cm broad, obtuse to broadly conic or convex, expanding to obtusely umbonate or nearly plane, surface glutinous to viscid, shining when dry, orange-fulvous to deep ferruginous and finally dark vinaceous-brown (near "Roods brown"), decorated with superficial brown fibrillose scales from remains of a veil, veil particles pallid on drying out, margin opaque and often decorated with remnants of the veil. Context thick, pallid; odor not distinctive, taste not recorded.

Lamellae adnate to subdecurrent or sinuate and with a decurrent tooth, at times rounded next to the stipe, close, very broad, whitish becoming grayish and at length rusty-umber, edge crenulate and beaded with white drops.

Stipe 3-10 (15) cm long, 5-15 mm thick, equal or nearly so, fibrous and firm, stuffed becoming hollow, pallid to grayish above, dark brown below, squarrose with brown scales up to the annulus, apex pruinose.

Spores 10-15 (18) x 5.5-7 (8.5) µ, smooth, with an apical discontinuity projecting only through the thick inner layer, wall at maturity 1-1.5 µ thick, in face view subfusoid, in profile more or less inequilateral or at least the ventral line straighter than the dorsal line, apiculate at base, in KOH dark cinnamon, in Melzer's reagent nearly tawny.

Basidia 4-spored, 30-36 x 7-9 µ, narrowly clavate, hyaline in KOH (hymenium hyaline) yellowish pallid in Melzer's reagent, projecting prominently when sporulating. Pleurocystidia none. (Occasional giant basidia present, some with one sterigma?). Cheilocystidia abundant, 43-75 x 4-9 µ, cylindric-clavate with pedicels flexuous, at times subcapitate, hyaline in KOH, wall thin and smooth, content homogeneous. Caulocystidia resembling the cheilocystidia but up to 100 µ or more long, content yellowish in KOH, homogeneous.

Gill trama of subparallel hyphae with greatly elongated wide (5-12 µ) cells; walls thin, smooth and perfectly hyaline in KOH, subhymenium a narrow hyaline gelatinous zone of narrow thin-walled hyphae. Pileus cutis a thick gelatinous layer (200 µ thick) of hyaline to yellowish narrow gelatinous hyphae appressed-interwoven; hypodermium not differentiated. Hyphae of context of inflated cells, hyaline in KOH, with somewhat thickened (about 0.5 µ) walls toward gill-trama, smooth, with small (3-6 µ) hyaline refractive oval to circular bodies numerous in the area above the gill trama (as revived in KOH). All hyphae inamyloid. Clamp connections present.

Habit, Habitat, and Distribution: Singly or in groups of two or three, on maple and perhaps other hardwood species, trunks, stumps, and logs, rarely on hemlock (Smith 50096); New Hampshire, New York, North Carolina, Tennessee, Michigan, Wisconsin, also Canada west to New Mexico; July to October; seldom abundant but not uncommon.

Observations: The apex of the spore in this species recalls the condition observed in Agrocybe erebia, but this is hardly sufficient reason for transferring the species to Agrocybe. Apparently there is a layer of colored hyphae below the gelatinous pellicle in old specimens but not in young well-dried material. The pleurocystidia, if they are not monosporous basidia, are rare and difficult to find. Although the spores are a very dark brown they are not violaceous, so there appears to be no good reason for transferring the species to Stropharia as was done by Kreisel.

Barrows and Isaacs collected this species in New Mexico on Populus (cottonwood), and also growing caespitose on stumps of Pinus ponderosa. The spores in the latter collection are small (10-12 µ long) but the specimens are immature. The stipes were exceptionally scaly. To say the least, pine is a most unusual host for this species.

Material Examined: MICHIGAN: Harding 167, 234, 336, 383; Kauffman (no date), 8-4-05, 7-26-09, 10-13-26, 9-1906; Mains 32-528, 32-233; Pennington 8-30-06; Peters 1121; Smith 11116, 23483, 32957, 33789, 36655, 37286, 37485, 38028, 38375, 39308, 50096, 50447, 57354, 67435, 67372; Stuntz 7-31-49; Thiers 3267, 3902, 4269, 4374, 4405. NEW MEXICO: Isaacs 2708, 2695. NEW YORK: Type, North Elba; Smith 97, 130; NORTH CAROLINA: Sharp 20501; Smith 10703. Oregon: Smith 24716. TENNESSEE: Hesler 18040. CANADA-Nova Scotia: Wehmeyer 762; Ontario: Kelly 951, 1720; Smith 26465; Quebec: Smith 61713.