The North American Species of Pholiota

110. Pholiota subvelutipes sp. nov.

Illustrations: Text figs. 229-232; pl. 52.

Pileus 4-7 cm latus, convexus demum planus, ad marginem appendiculatus, luteus, glutinosus, squamosus. Contextus albus. Lamellae pallidae vel griseo-olivaceae, demum subfulvae, confertae latae, adnatae. Stipes 4-8 cm longus, 5-11 mm crassus, ad basim velutino-pubescens, deorsum squamosus, sursum pallidus demum pallide luteus. Velum luteum. Sporae 6.5-8 (9) x 3-4 µ, leves, oblongae. Pleurocystidia 30-46 x 7-11 µ sordide brunnea. Cheilocystidia 23-35 x 4-9 µ. Specimen typicum in Herb. Univ. Mich. conservatum est., legit prope Rock River, Mich. 25 Sept. 1929. A. H. Smith.

Pileus 4-7 cm, broad, convex expanding to nearly plane, margin at first appendiculate with veil remnants, viscid to glutinous when young or wet, ground color bright pale yellow ("Pinard-yellow" to "empire-yellow") bruising to olivaceous ("sulphine-yellow"), on aging ferruginous from the center out, surface at first decorated with concentrically arranged amber-brown ("amber-brown") scales about 3 mm in diameter and triangular near cap margin but subconic on the disc; margin even. Context white when young, flavescent moderately thick and pliant.

Lamellae adnate to adnate-emarginate with a tooth, 5-7 mm broad, crowded, when young pallid to "olive-buff," becoming avellaneous and finally clay-color, edges minutely floccose.

Stipe 4-8 cm long, 5-11 mm thick, equal to a flange-like enlargement at base and base surrounded by a radiating mass of olive-yellow to tawny pubescence, solid, whitish within at first, lutescent or finally fulvous below, the annular zone covered with closely set projecting yellow scales which became tawny in age, naked above the veil line. Veil pale yellow, almost cortinate.

Spores 6.5-8 (9) x 3-4 µ, smooth, apical pore present but minute, apex not truncate; shape in face view oblong to elliptic, in profile oblong to elliptic (often narrower by 0.3 µ in profile than in face view); color in KOH dull tawny, not much change in Melzer's reagent; wall about 0.25 µ thick.

Basidia 26-33 x 6-7.5 µ, 4-spored, narrowly clavate, hyaline in KOH in properly dried material, yellowish in Melzer's reagent. Pleurocystidia 30-46 x 7-11 µ, subclavate to narrowly ovate-pedicellate or nearer fusoid-ventricose; wall thin smooth and hyaline; content dark bister to very dull brown and filling the cell, coagulating in drying but not forming a distinctive body (inclusion) dark dingy brown as revived in Melzer's reagent; projecting 8-12 µ, some cells hyaline or only weakly colored. Cheilocystidia 23-35 x 4-9 µ, clavate, clavate-irregular, fusoid-ventricose, ventricose-capitate or merely subfusoid, wall thin smooth and hyaline, content homogeneous, typically hyaline. Caulocystidia as clavate end-cells of surface hyphae 30-75 x 4-7 µ, hyaline, thin-walled, smooth, content homogeneous.

Gill trama with a floccose central strand of subparallel hyphae hyaline to pale tan (in KOH), walls thin and smooth; subhymenium a rather wide gelatinous band of narrow hyaline interwoven hyphae. Pileus cutis a thick pellicle of gelatinous hyphae 2-5 µ diam., ochraceous to pale dingy brownish or hyaline in KOH; hypodermial layer scarcely differentiated. Context hyphae with slightly thickened refractive walls (in KOH) showing as a pair of double lines, smooth; hyphal cells considerably inflated. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: Caespitose on log of Betula lutea, Rock River, Mich. Sept. 25, 1929. Coll. A. H. Smith (type).

Observations: This species was reported as P. subsquarrosa by Kauffman and Smith (1933). However, P. subsquarrosa is still not clearly defined by European authors, so at this time it appears best to report on the 1929 collection as a separate species. It is readily distinct from P. squarroso-adiposa by its narrower more oblong spores and velvety mycelium at the base of the stipe. In addition the gills are not yellow at first. It is at once distinguished from P. connata in the field by the scaly stipe and flanged stipe-base. We have one collection, Smith 73596 on Abies wood from near Kellog, Idaho, which has the basal mycelium of P. subvelutipes but its gills are subdistant and when young yellow. This points up, again, the pattern of variability in the group and the various combinations of characters found to exist when large numbers of collections are studied. The Kellog collection may represent a distinct species but at present we do not care to describe it.