The North American Species of Pholiota

121. Pholiota castanea sp. nov.

Illustrations: Text figs. 262-265; pl. 59a.

Pilcus 3-5 cm latus, convexus, demum late-convexus vel depressus, glaber, viscidus, subcastaneus. Contextus albidus. Lamellae emarginatae, latae, confertae, albidae demum luteae. Stipes 1-6 cm longus, 1-6 mm crassus, pallidus, fibrillosus. Sporae 6-7.5 (8) x 3.5-4 µ. Pleurocystidia dimorpha: 1) 45-72 x 10-14 µ, fusoide-ventricosa. 2) 12-18 x 4-6 µ, ventricosa, rostrata vel fusoide ventricosa vel elliptica. Specimen typicum in Herb. Univ. Tenn. conservatlum est; legit prope Knoxville, Tenn. Hesler 20269.

Pileus 3-5 cm broad, convex, finally expanded-convex, in age at times depressed-concave, glabrous, viscid, "chestnut-brown" to "bister," paler when young (near "tawny"), margin even. Context thin, firm, white; odor and taste mild.

Lamellae emarginate, white when young, finally "tawny-olive" or slightly darker, close or crowded, rather broad, edges slightly eroded.

Stipe 4-6 cm long, 4-6 mm thick, tapering downward, pallid then dingy, fibrillose, solid or somewhat stuffed. Veil webby, yellowish, evanescent, leaving an evanescent ring.

Spores 6-7.5 (8) x 3.5-4 µ, oblong to elliptic in face view, oblong to slightly bean-shaped in profile, smooth, dull cinnamon in KOH, paler cinnamon in Melzer's sol., wall slightly thickened (± 0.3 µ), apical pore distinct but apex not truncate.

Basidia 18-24 (27) x 5-6 µ, 4-spored, ochraceous in KOH on sections of hymenium (in mass), in Melzer's reagent yellowish. Pleurocystidia: 1) 45-72 x 10-14 µ, basically fusoid-ventricose but neck with distinct constrictions and often thick-walled in the constriction, apex obtuse to knobbed or with one or more bulgy proliferations, walls thin (except as noted above), surface smooth, content homogeneous and in KOH hyaline to ochraceous. 2) 12-18 x 4-6 µ, ventricose-rostrate to fusoid ventricose to elliptic and then about 18 x 8 µ, hyaline thin-walled, smooth, content homogeneous, buried in hymenium. Cheilocystidia 26-38 x 6-9 µ (12) µ, subfusoid, to fusoid-ventricose, thin-walled, yellow in KOH mostly, and content homogeneous. Caulocystidia in agglutinated tufts, 18-35 x 4-9 µ, versiform, (basidium-like, contorted, subfusoid, or filamentose), yellow in KOH, walls smooth.

Gill trama of filamentose subparallel to interwoven hyphae with elongate cells 8-20 µ broad, walls slightly thickened (middle-lamella evident), refractive, smooth and ochraceous in KOH; subhymenium cellular; cells 3-6 µ diam. and walls not gelatinous. Pileus cutis a thick gelatinous layer of narrow (2-3 µ) ochraceous smooth hyphae easily torn away in sectioning; hypodermium orange-rusty in KOH from floccose encrusted hyphae 8-18 µ or more broad, walls thin to slightly thickened. Context hyphae smooth, inflated, walls slightly thickened (0.5 µ ±) as revived in KOH and somewhat refractive. All hyphae inamyloid. Clamp connections present.

Habit, Habitat, and Distribution: On soil and rotten wood, near Knoxville, Tenn. Dec. 11, 1951. A. J. Sharp, (Hesler 20269, type).

Observations: This species and P. olivaceophylla lack the gelatinous subhymenium featuring most species with the prominent pleurocystidia. In the dried state the gills are decidedly yellowish. The aspect of the basidiocarps is that of a dingy P. spumosa but the subhymenium of the latter distinguishes it. The very small and very large pleurocystidia is an interesting combination. The cheilocystidia should be re-studied from fresh material.