The North American Species of Pholiota

96. Pholiota squarrosa (Fr.) Kummer, Der Führer in die Pilzkunde. p. 84. 1871.

Agaricus squarrosus Fries, Syst. Myc. 1: 243. 1821.
Dryophila squarrosa (Fr.) Quélet, Enchir, Fung., p. 68. 1886.
Hypodendrum floccosum (Schaeff.) Overholts, North Amer. Fl. 10: 280. 1932. var. squarrosa

Illustrations: Pls. 41, 42, 43.

Pileus, 3-10 (12) cm broad, obtuse to convex when young, the margin incurved, becoming campanulate with a conic umbo to broadly convex or nearly plane, surface dry, cuticle broken up into numerous innate, recurved, or squarrose, scales, the margin at first conspicuously fringed with veil remnants, cuticle sometimes denuded along the edge leaving a glabrous margin, scales "cinnamon-buff" to "clay-color" and becoming dull tawny at maturity (light to dark yellowish brown), pale yellow between the scales, or in age pale greenish yellow along the margin. Context moderately thick and pliant, pale yellowish; odor none (or garlic in Smith 35793, 50928, 51814, 59711; of onion in Smith 51425, 51602, 52961), taste mild or slightly rancid.

Lamellae bluntly adnate to somewhat arcuate and with a decurrent line or tooth, close to crowded, narrow, pale yellowish when young, soon more or less sordid greenish yellow ("Isabella color"), and finally sordid rusty brown, edges even.

Stipe 4-10 (12) cm long, 4-12 (15) mm thick, equal or nearly so, at times tapered to a long strigose pointed base, solid, dry, yellowish within, surface covered with recurved pale tawny scales up to the annular zone, annulus often evanescent but sometimes membranous and persistent (and then pileus margin not conspicuously appendiculate).

Spores (5) 6-7.5 (8) x 3.8-4.5 µ, smooth, apical pore distinct but apex not truncate; shape in face view elliptic to ovate, in profile obscurely inequilateral to bean-shaped; dull tawny in KOH and near cinnamon in Melzer's reagent, wall about 0.25 µ thick.

Basidia (16) 20-25 x 5-7 µ, 4-spored, clavate, hyaline in KOH, yellowish in Melzer's reagent. Pleurocystidia present as chrysocystidia (26) 30-48 x (6) 8-16 µ, clavate to clavate-mucronate, apex papillate or drawn into a distinct projection, walls thin and smooth, refractive inclusion hyaline in KOH and dextrinoid in Melzer's reagent. Second type elliptic to oval-pedicellate or clavate, 30-45 x 9-14 µ, hyaline and evenly refractive throughout in KOH, yellowish in Melzer's reagent; walls thin and smooth. Cheilocystidia 18-43 x 5-15 µ, subfusoid, fusoid-ventricose, clavate or clavate-mucronate, some with highly refractive context. Caulocystidia present as filamentose-clavate cells 6-9 µ wide at apex, content homogeneous.

Gill trama of parallel floccose hyphae 5-8 µ broad or in age more inflated, walls thin smooth and hyaline, yellowish in KOH and Melzer's reagent; subhymenium of narrow (2-4 µ) gelatinous hyphae in a distinct layer. Pileus cutis a "collapsed" trichodermium of septate brown hyphae with smooth to incrusted walls, the terminal cell of a hypha clavate, subcylindric or fusoid-ventricose (cystidioid) 50-70 x 10-20 µ. Clamp connections present but not always abundant. All hyphae inamyloid.

Habit, Habitat, and Distribution: Caespitose on living conifer and hardwood trees, at the base of living or dead trees, or on logs and stumps, Michigan, Colorado, New Mexico, Idaho, Wyoming; also reported by Overholts (1927) from Maine, Massachusetts, New York, District of Columbia, Pennsylvania; and from Wisconsin by Harper (1913); and from Canada.

Observations: This is a showy, wood-inhabiting, conspicuously scaly Pholiota, with a dry pileus. The taste becomes more disagreeable as the basidiocarps age. The odor of garlic or onion reported for a number of collections however, as in Smith 59902 and 72388, is not dependent on the aging of the basidiocarps. The greenish gills in age will usually distinguish this species in the field from P. squarrosoides.

Material Examined: COLORADO: Barrows 1418 (MICH); Smith 51425, 51602, 51814, 52435, 52961; IDAHO: Gruber P-23, P-53; Smith 15949, 46512, 47138, 53273, 59283, 59711, 59873, 60094, 60460, 60188, 66327, 69962; Solheim 5011; MICHIGAN: Shaffer 3787 (MICH); Smith 34135, 36093, 38316, 50156, 50928, 72388, 72691; Thiers 4426 (MICH); MINNESOTA: Kaplan 18; NEW MEXICO: Barrows 796, no number (1955); NEW YORK: Korf (no number) 1944; WYOMING: Smith 35409, 35793, 36239; Solheim 3094, 3561, 5083, 5160, 5161, 5214, 5220, 5327, 5444, 5959, 5990, 6259 (all MICH); Wehmeyer 4, 10 (MICH); CANADA: ONTARIO: Bell 4746 (TENN); Harper 9-1902 (MICH); Jackson 3711 (MICH); Smith 4561, 26545; AUSTRIA: Lowhag 1934 (MICH); FRANCE: Josserand 24-10-37; NETHERLANDS: Geestranus 9047; SWEDEN: Haglund 530; SWITZERLAND: Favre 2 colls. (MICH).