The North American Species of Pholiota

144. Pholiota occidentalis var. occidentalis sp. nov.

Illustrations: Text figs. 311-314; pl. 67b.

Pileus (2)2.5-6.5 cm latus, late umbonatus, cinnamomeus, viscidus. Lamellae adnatae, angustae, subdistantes, pallidae demum argillaceae. Stipes 3-4 cm longus, 4-8 mm crassus, albidus, deorsum subfulvus. Sporae 5.5-7 x 4-4.5 µ. Pleurocystidia 44-87 x 9-15 µ. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Mt. Hood. Ore., 2 Oct. 1944. Smith 19388.

Pileus (2) 2.5-6.5 cm broad, obtuse becoming broadly umbonate, "cinnamon" when young, becoming "pale cinnamon-buff" along the margin, in age often more or less avellaneous over the water-soaked marginal area, glutinous, with fibrillose remains of the veil scattered along the margin, fibrils beneath the gluten finally becoming aggregated to form appressed fascicles. Context thick in the disc, pallid to pale watery buff; odor and taste not distinctive.

Lamellae broadly adnate to almost arcuate or slightly decurrent, white, finally becoming pale clay-color, nearly close to subdistant, 1-2 tiers of lamellae, narrow, broadest near stipe (3-4 mm), edges even.

Stipe 3-4 cm long, 4-8 mm thick, equal, solid, whitish, in age with a cinnamon tinge, more or less silky-fibrillose from the remains of the thin fibrillose veil, in age slightly darker at base (dark sordid brown). Veil white, arachnoid.

Spores 5.5-7 x 4-4.5 µ, smooth, apical pore small but distinct, shape elliptic to subovate in face view, in profile obscurely bean-shaped varying to obscurely inequilateral, color in KOH ochraceous tawny, in Melzer's reagent paler ochraceous; wall thin (about 0.2 µ).

Basidia 18-24 x 5-7 (8) µ, 4-spored, subclavate, hyaline to yellowish in KOH, yellowish in Melzer's sol. Pleurocystidia 44-87 x 9-15 µ, fusoid-ventricose, apex obtuse to subacute, smooth, wall thin or up to 1 µ thick (rarely thicker), content homogeneous, lemon yellow revived in KOH but soon fading, neck often filled with homogeneous colloidal content. Cheilocystidia 30-50 x 7-14 µ, obtusely fusoid to fusoid-ventricose, varying to subclavate, lemon-yellow in KOH, wall thin and smooth. Caulocystidia 28-80 x (4) 6-14(18) µ, versiform (cylindric, fusoid, fusoid-ventricose or subclavate) smooth, walls thin to slightly thickened, yellowish in KOH to nearly hyaline, content homogeneous.

Gill trama of a central region of parallel hyphae, or in age somewhat interwoven, the cells becoming inflated, walls smooth, thin, pale yellow in KOH; subhymenium gelatinous, of narrow (2-3 µ) hyphae in subparallel to interwoven arrangement. Pileus cutis a thick gelatinous pellicle with narrow (2-2.5 µ) yellowish hyphae dispersed widely in it, the hyphal walls smooth to slightly encrusted, in age many reticulated or creased transversely; hypodermial zone of floccose narrow hyphae 3-8 µ with rusty brown walls smooth or with slight incrustations. Context hyphae inflated, with smooth thin yellowish to greenish-yellow walls. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: On alder branches and debris but also on conifer wood, Pacific Northwest, September-October.

Observations: This is a small pale cinnamon species very common on the remains of alder and other hardwoods in the Pacific Northwest. The flesh is pallid, and the lamellae, veil, and stipe are white. It appears related to P. subfulva and P. decorata. The color (ochraceous tawny) of the spores in KOH is unusual in this group, and the pleurocystidia often have the thickened wall almost obscured by the content of the cell which has about the same index of refraction. Broken cystidia with the content escaped are best for measuring wall thickness.

Material Examined: (on alder): OREGON: Smith 19239, 19239a, 19388 (type). (On conifer wood): IDAHO: Smith 23531, 44311, 44340, 44341, 44485, 46594, 47117, 47117a, 53886, 55223, 58470, 58521, 58631, 58690, 68820, 69620, 70091, 70261, 73316, 73582, 73588, 73662, 73959, 73977, 74070. OREGON: Smith 23669, 23916, 23975, 24005, 27374. WASHINGTON: Smith 16727, 30627, 30731.