The North American Species of Pholiota

196. Pholiota crassipedes nom. nov.

(not P. lata Kummer p. 85, 1871)
Gymnopilus latus Murrill, Mycologia 4: 257. 1912.
Flammula lata Murrill, Mycologia 4: 262. 1912.

Illustrations: Text figs. 442-444.

Pileus gregarious, reaching 9 cm broad, convex to plane, not umbonate, ferruginous-fulvous at the center, ochroleucous on the margin, glabrous, shining, viscid, radiate-lineate. Context rather tlin; taste mild.

Lamellae sinuate or adnate, pallid to fulvous, plane, not crowded, rather narrow.

Stipe 5-7 cm long, 1-1.3 cm thick, equal or slightly larger below. dry smooth, subglabrous, fleshy, white or somewhat yellowish, with yellow or orange mycelium at the base. Veil pale yellow, membranous in young hymenophores, soon breaking into fibrils and disappearing.

Spores 5.5-7 x 3.5-4.5 µ, smooth, germ pore present but very minute; shape in face view elliptic to ovate, in profile subelliptic to obscurely inequilateral; as revived in KOH more or less ochraceous tawny, paler cinnamon in Melzer's reagent; wall about 0.25 µ thick.

Basidia 20-27 x 5-7 µ, 4-spored, pale ochraceous in KOH and in Melzer's reagent. Pleurocystidia: 1) abundant, 38-73 x 7-21 µ, fusoid-ventricose, apex obtuse, wall thin smooth and hyaline, content usually ochraceous to amber-brown from colloidal content which in some is shrunken and coagulated: 2) 12-20 x 4-9 µ, subfilamentous to clavate, with thin smooth hyaline walls, content consisting of an irregular mass of hyaline-refractive material (not as well organized as in "chrysocystidia") or the refractive material in rods, bars or particles and variously distributed in the cell (the same material seen in some basidia and in some of the large fusoid-ventricose cells). Cheilocystidia 43-57 x 7 -14 µ, similar to pleurocystidia or subfusoid (neck not elongated). Caulocystidia none found.

Gill trama a central area of floccose subparallel hyphae (3) 4-10 µ diam. cells finally inflated, walls thin smooth and yellowish to hyaline in KOH; subhymenium of gelatinous narrow (2 µ) hyaline hyphae. Pileus cutis a gelatinous pellicle of loosely interwoven ochraceous narrow (2-4 µ) smooth to encrusted hyphae; hypodermial region of floccose rusty brown incrusted hyphae 3-9 µ diam. Context hyphae interwoven, of inflated cells with smooth thin yellowish to hyaline walls in KOH. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: On a log of a deciduous tree in woods, Washington, fall. Known only from the type.

Observations: Our microscopic data are from the type. This is near P. jalapensis, which becomes slightly greenish where bruised, has stramineous gills and pale spores. Kauffman (1926) examined specimens from dead willow trunks and found the stipe apparently viscid (Murrill described it as dry). Kauffman stated that the large pilei and solid stipe would separate it from the "spumosa" group. He apparently had some other species. P. crassipedes is close to P. lubrica but the latter has white mycelium around the base and grows under conifers. However, both should be critically compared from fresh material.

Because of the bright color, even of dried specimens, one is reminded of the P. alnicola group but the large hymenial cystidia and the failure of the spores to become dark reddish cinnamon in Melzer's reagent rule it out. P. crassipedes has the stature of P. lubrica and the cystidia are consistently thin-walled. We are not inclined to emphasize the "chrysocystidioid cells" in the hymenium as a taxonomic character in the present stage of our knowledge of this species, but they are not without interest from the standpoint of the evolution of chrysocystidia from basidioles. It differs from P. sublubrica in growing on hardwood logs and in having yellow to orange mycelium at the stipe base. Also P. sublubrica typically has veil remnants on the pileus. The color of the spores in KOH, however, is the same in both.