The North American Species of Pholiota

26. Pholiota erinacea (Fr.) Rea, Brit. Basid. P. 121. 1922.

Agaricus erinaceus Fries, El. Fung. p. 33. 1828.
Naucoria erinaceus (Fr.) Gillet, Champ de Fr. p. 543. 1874.
Dryophila erinacea (Fr.) Quélet Enchir. Fung. p. 69. 1886.
Agaricus aridus Persoon, Myc. Eur. 3: 193. 1828.
Phaeomarasmius aridus (Pers.) Singer, Lilloa 22: 577. 1951.
Phaeomarasmius erinaceus (Fr.) Kühner, 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) µ, 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 µ, hyaline to pale ochraceous in KOH and Melzer's reagent, narrowly clavate. Pleurocystidia scattered, 30-42 x 7-10 µ, fusoid-ventricose with subacute apex, hyaline, thin-walled, smooth, in some pilei apparently absent. Cheilocystidia 20-35 x 4-9 µ, 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 µ diam., also seta-like cells present 50-100 x 7-9 µ 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 thick-walled hyphae the cells tubular to inflated and with walls heavily incrusted, hyphae with end-cells tubular to cystidioid, cells 6-9 µ diam. when tubular and up to 15 µ 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.

Observations: The spore size is variable in this species as is also the number of sterigmata borne on a basidium. Hence we have not attempted to recognize variants based on this feature. The spores described here for Harding 261 are very similar to those described by Kühner & Romagnesi (1953). Josserand and Smith (1941) made a critical comparison of European and North American material.

It should also be pointed out here that the spores are intermediate between the Pholiota and Tubaria types. Since the species has been placed previously in Pholiota we include it here for practical reasons pending a critical restudy of Phaeomarasmius, Tubaria and Flocculina. Such a study should include EM photographs of the spores. Singer (1963, p. 595) states: "After having worked with Phaeomarasmius intensively in several continents, I have come to the conclusion that the arrangement first proposed by me in 1947 and maintained here is correct." On the basis of our study as of the present, and as indicated earlier, we would limit Phaeomarasmius to his subgenus and section under that name. His subgenus Carpophilus in our estimation does not give sufficient emphasis to the typical Pholiota-type of spore as found in many of its species.