The North American Species of Pholiota

83. Pholiota prolixa sp. nov.

Illustrations: Text figs. 117-119, 120; pls. 33, 70a.

Pileus 1.5-4 (6) cm latus, obtutus demum convexus vel late umbonatus, viscidus, vel glutinosus, glaber, melleus vel ad centrum sordide argillaceus. Contextus cartilagineus, luteolous. Lamellae adnatae, angustae, confertae, luteolae demum subcinnamomeae. Stipes 3-5 cm longus, 1.5-4 mm crassus, aequalis, luteolus, deorsum subfulvus, fibrillose squamulosus. Sporae 6-8 x 3-4 (4.5) µ. Chrysocystidia 26-40 x 6-12 (15) µ, fusoide ventricosa vel clavato-mucronata. Specimen typicum in Univ. of Mich. conservatum est; legit prope. Lakeland, Michigan, 4 Oct. 1936; Smith 5027.

Pileus (1.5) 2-4 (6) cm broad, broadly convex with an incurved margin, in age broadly convex-depressed with a decurved margin, "honey-yellow" to "yellow-ocher" over all when young, in age the margin paler and the disc "ochraceous-tawny," glabrous, glutinous, margin somewhat appendiculate from the submembranous veil, often appearing fibrillose-streaked beneath the gluten. Context cartilaginous tough, yellowish; odor not distinctive, taste slightly disagreeable.

Lamellae adnate, pale yellow to pallid, slowly becoming dull brownish with a slight chocolate shade, crowded, narrow (3 mm), tapering outward, edges becoming slightly eroded.

Stipe 3-5 cm long, 2-4 mm thick at apex, narrowed downward, hollow, rigid-fragile, yellowish over apical region, sordid tawny below, with scattered patches of fibrils to appressed fibrillose-squamulose below, annular zone interrupted and soon evanescent, punctate-fibrillose over apex.

Spores (5.5) 6.5-8 (9) x 3.5-4.5 (5) µ, smooth, apical pore very minute (under 1.4 NA ob.), shape in face view elliptic to ovate, in profile elliptic to obscurely inequilateral; yellowish tawny revived in KOH, merely ochraceous in Melzer's reagent; wall moderately thick (about 0.25-0.3 µ); apex not truncate.

Basidia 16-22 (26) x 4-5 (6) µ, 4-spored, clavate, yellowish in KOH and Melzer's reagent. Pleurocystidia of two types: 1) chrysocystidia 32-45 x 8-12 (15) µ, with a broad basal region, ventricose above and tapered to a subacute apex rarely merely clavate to elliptic with a pedicel, with a large amorphous highly refractive hyaline inclusion, the inclusion orange-brown to reddish in Melzer's reagent; 2) a few pedicellate-ellipsoid and completely filled with flavous homogeneous pigment, 26-35 x 7-11 µ. Cheilocystidia of two types; 1) similar to chrysocystidia on gill faces and 2) cylindric-obtuse to narrowly ventricose at base, 25-40 x 3.5-6 (8) µ, content homogeneous, hyaline to yellowish. Caulocystidia 28-47 x 5-15 µ versiform, some with coagulated content.

Gill trama of subparallel floccose hyphae ochraceous to tan as revived in KOH, walls thin, smooth; subhymenium a very thin layer of hyaline narrow subparallel gelatinous hyphae and gelatinization extending into the base of the hymenium. Pileus cutis a gelatinous layer of tangled hyphae 2-4 µ diam., with ochraceous to rusty incrustations; hypodermium of floccose heavily encrusted (ochraceous-rusty) hyphae grading into the paler context which is of greatly inflated (to 20 µ or more) hyphal cells with smooth ochraceous tawny or yellower walls. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: Caespitose around stumps on soil in low swampy elm woods, late summer and fall, common, Ohio and Michigan.

Observations: This is a well characterized species in southeastern Michigan, both in the field and in the herbarium. It begins to fruit in August and builds up to a peak around the middle of September if the weather is moist.

We tried to recognize several species in this group but the combinations of characters were not constant. The veil is poorly developed on the small early season or very late season fruitings. At times some leptocystidia similar in shape to the slender cheilocystidia are seen but are not very constant. The diagnostic field features are narrow, close to crowded lamellae yellowish before maturity, fibrillose to submembranous veil on the stipe which in robust specimens leaves a weak annulus, the very numerous chrysocystidia with their refractive content changing to orange brown or nearly red in Melzer's reagent, and the slender cheilocystidia for the most part. In all of them clavate-pedicellate to elliptic-pedicellate pleurocystidia with flavous to tawny homogeneous to wrinkled content (revived in KOH) are usually readily demonstrated.

Material Examined: OHIO: Walters 174. MICHIGAN: Harding 394, 418, 419, 421; Kauffman 11-7-19, 8-7-25 (type); Smith 33-1109, 20553, 50545, 50725, 50727, 72561, 72614, 73249, 73281, 9-28-33.