The North American Species of Pholiota

143. Pholiota verna sp. nov.

Illustrations: Text figs. 307-308; 309-310; pl. 66.

Pileus 6-12 cm latus, late convex us, virgatus, viscidus, demum subsquamulosus, fulvus, ad marginem subluteus. Contextus albus. Lamellae confertae latae, adnatae, albidae demum subfulvae. Stipes 4-6 cm longus, 10-12 mm crassus, aequalis, farctus demum cavus, albidus, deorsum demum sordide luteo-brunneus, sursum sericeus. Velum fibrillosum. Sporae 6-7 x 3.5-4 µ. Pleurocystidia crassotunicata, 60-85 x 9-14 µ, flexuosa. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Oil City, Hoh River, Olympic National Forest, Wash. 7 Mai 1939, Smith 13176.

Pileus 6-12 cm broad, broadly convex becoming plane or with a somewhat wavy turned up margin at maturity, surface virgate beneath a thin gelatinous pellicle, in age the margin often with agglutinated spot-like scales from the broken cuticle (not from veil remnants) color "tawny" on disc (fulvous), paler to the margin, at times whitish at first and decorated with inconspicuous patches of veil remnants. Context thick (5-6 mm near disc), whitish with a watery line above the gills, firm, odor and taste none.

Lamellae close (67-78 reach stipe), broad (8-10 mm), adnate or slightly adnexed, toothed, 2-3 tiers of lamellulae, white when young, near "tawny-olive" (yellow-brown) at maturity, edges even.

Stipe 4-6 cm long, 10-12 mm thick, equal, stuffed, becoming hollow, fleshy, surface white and at first fibrillose from veil, becoming dingy yellowish to bister from the base upward on aging, apex silky and remaining whitish. Annular fibrillose zone left by veil soon evanescent.

Spores 6-7 x 3.5-4 µ, oblong, or ovate or narrowly elliptic in face view, in profile mostly slightly bean-shaped to elliptic, apical pore extremely minute, color in KOH pale tawny, in Melzer's pale tawny but dull and some giving impression of being faintly amyloid, in H2O mounts when fresh distinctly reddish, wall thin (0.25 µ ±).

Basidia 4-spored, 25-32 x 6-8 µ, clavate, hyaline to ochraceous revived in KOH and in Melzer's sol. Pleurocystidia abundant, 1) 36-50 x 8-12 µ and elliptic to ovate-pedicellate, walls 1-2 µ thick as revived in KOH, content usually yellowish and colloidal. 2) 60-85 x 9-14 µ almost subcylindric-flexuous or somewhat ventricose above the long narrow pedicel, walls as revived in KOH 1-2 µ thick but thickening generally irregular, apex subacute to obtuse, content colloidal and homogeneous, hyaline to ochraceous in KOH, surface smooth or a slight amount of debris adhering. Amyloid debris scattered in a few places along hymenium. Cheilocystidia resembling pleurocystidia but smaller and some enlarged basidioles (?) present. Caulocystidia none.

Gill trama of parallel to slightly interwoven hyphae with cells finally enlarged to 10-20 µ diam., and mostly greatly elongated; walls pale tan to greenish yellow or hyaline as revived in KOH, thin, smooth, rather refractive; subhymenium a conspicuous broad gelatinous band of narrow hyaline branched hyphae. Pileus cutis a pellicle (gelatinous), the hyphae appressed, ochraceous in KOH and more or less incrusted, the cross walls highly refractive in KOH; hypodermial region of floccose more heavily incrusted hyphae 5-12µ diam. and bright fulvous to orange-fulvous in KOH. Context hyphae, mostly smooth, interwoven, yellowish to yellowish-hyaline in KOH, cells greatly inflated, walls at times up to 1 µ thick in area beneath hypodermium. All hyphae inamyloid. Clamp connections present.

Habit, Habitat, and Distribution: Gregarious on debris of Populus trichocarpa, Hoh River, Olympic National Forest, Wash., May 7, 1939. Smith 13176, type.

Observations: The greatly elongated flexuous cystidia which are thick-walled as revived in KOH are a most peculiar feature, and exclude the species from P. lubrica with which it had been identified in the field. Cystidial features also exclude it from P. avellaneifolia and P. sublubrica which have generally the same aspect. In Smith 14692 from the same area the cystidia are less flexuous and more are fusoid-ventricose. It was also collected on debris of cottonwood. When first mounted in KOH most of the cystidia are collapsed and were thin-walled but on standing ten to fifteen minutes they assume their typical shape and show a wall at least thick enough to measure accurately. Many of the cystidia had debris adhering on or around the apex.