The North American Species of Pholiota

169. Pholiota subamara sp. nov.

Illustrations: Text figs. 514-516.

Pileus 3-9 cm latus, convexus, demum planus vel late depressus, rare subumbonatus, viscidus, luteus, ad marginem striatulus. Contextus subluteus. Sapor tarde amarus. Stipes 4-10 cm longus, 3-6 mm crassus, flexuosus, luteus, siccus, fibrillosus, cavus. Sporae in cumulo hepaticolor, 7-9 x 4-5 µ, leves. Pleurocystidia 48-70 x 9-15 µ, fusoide ventricosa. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Cades Cove, G.S.M.N.P., 9 Nov. 1940. L. R. Hesier 12950.

Pileus 3-9 cm broad, convex, then expanded, finally plane and slightly depressed, at times slightly umbonate, very viscid, at first "ochraceous-buff" to "antimony-yellow," then "yellow-ochre," disc usually darker, radiately brown-fibrillose, at times with scale-like patches of veil remnants margin striatulate when wet, even when dry. Context thin, pliant, yellowish with an olive-ochre tint; odor like wood, taste mild then slightly bitter.

Lamellae adnate, with a decurrent tooth, seceding (as the pileus expands), "amber-yellow," at first, then "tawny-olive" to "buckthorn brown," close, broad, rounded behind, many short, edges fimbriate.

Stipe 4-10 cm long, 3-6 mm thick, flexuous, concolorous with the pileus, dry, fibrillose, hollow. Veil usually evanescent.

Spores 7-9 x 4-5 µ smooth, apical pore distinct; liver color in deposit; shape ovate to elliptic in face view, in profile obscurely inequilateral to slightly bean-shaped; in KOH dull tawny, in Melzer's reagent ochraceous buff; wall about 0.3 µ thick.

Basidia 25-28 x 5-7 µ, 4-spored, clavate, yellow in KOH and merely duller in Melzer's reagent. Pleurocystidia 48-70 x 9-15 µ, fusoid-ventricose, apex obtuse, rarely forked, walls thin and smooth, content homogeneous and ochraceous to hyaline. Cheilocystidia 25-38 x 7-10 µ, fusoid to fusoid-ventricose; narrowly clavate or irregular in outline, thin-walled, smooth, content ochraceous to hyaline. Caulocystidia voluminous: 1) clavate and 18-28 x 9-14 µ, smooth, thin-walled, wall ochraceous in KOH, content homogeneous; 2) utriform, 46-70 x 9-16 µ, smooth, thin-walled. Content yellow to hyaline; 3) versiform-inflated and up to 60 x 30 µ.

Gill trama a central area of floccose hyphae with greatly elongated, wide cells yellow in KOH, thin-walled and smooth; subhymenium a thin gelatinous layer of hyaline narrow (2-3 µ) hyphae. Pileus cutis a gelatinous pellicle up to 200 µ thick with narrow ochraceous hyphae dispersed in it, hyphae smooth but collapsing and then wrinkled; hypodermial zone of tawny distinctly incrusted hyphae 4-10 µ diam. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: On stumps and logs of oak and pine, Tennessee, November; Hesler 12950, type.

Observations: Although apparently related to P. spumosa this species is distinct in the complex by its dark liver-colored spore deposit. Under the microscope, however, the color is normal for the group. Its spores are too large for P. flavida (6-7 x 4-4.5 µ as compared to 7-9 x 4-5 µ) in the sense of Moser.