The North American Species of Pholiota

74. Pholiota lutescens var. lutescens sp. nov.

Illustrations: Text figs. 85-87; pl. 30.

Pileus 2-5 (7) cm latus, convexus, viscidus, albus, tarde lutescens, ad marginem fibrillosus. Contextus albus demum luteus. Lamellae albae, demum luteae, adnatae, confertae, latae. Stipes 3-6 cm longus, 3-8 mm crassus, deorsum saepe attenuatus, albidus, tarde luteus, fibrillosus. Sporae 6.5-7.5 (8.5) x 3.5-4 (4.5) µ. Chrysocystidia 28-42 x 7-11 µ, clavato- mucronata vel fusoide ventricosa. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Sharon Hollow (Manchester), Mich., 5 Nov. 1960, Smith 63406.

Pileus 2-5 (7) cm broad, convex with an incurved margin, pure white at first, gradually becoming lemon-yellow from disc out, margin at first fibrillose-appendiculate from remains of thin veil, glabrous over central part, fibrillose toward the margin, slightly viscid from a thin gelatinous pellicle. Context white, subcartilaginous; odor and taste not distinctive.

Lamellae adnate, white when young, becoming pale yellow and finally dull rusty brown from spores, close, moderately broad, tapered to cap margin, 2-3 tiers of lamellulae.

Stipe 3-6 cm long, 3-8 mm at apex, narrower downward or equal, white overall and fibrillose squamulose up to the faint apical zone left by fibrillose veil, gradually lemon-yellow overall, base near "Isabella color," finally rather cartilaginous-pliant.

Spores 6.5-7.5 (8.5) x 3.5-4 (4.8) µ, ovate to oblong in face view, in profile obscurely inequilateral to slightly bean-shaped; germ pore evident and apex tending to be slightly truncate; wall about 0.3 µ thick; in KOH rich tawny, in Melzer's reagent paler and more cinnamon.

Basidia 21-27 x 5-6 µ, 4-spored, clavate, hyaline to yellowish in KOH and dingy ochraceous in Melzer's reagent. Pleurocystidia 28-42 x 7-11 µ, clavate-mucronate to fusoid-ventricose, at times with a slender neck tapered to an acute apex, wall smooth thin and hyaline; content a highly refractive amorphous body yellowish in Melzer's reagent. Cheilocystidia 23-31 x 3-6 µ, cylindric with rounded to subcapitate apex or with a slight medial inflation in addition varying to fusoid-ventricose with obtuse apex. Caulocystidia present but not abundant, resembling those of var. robusta except that chrysocystidia were not observed.

Gill trama of a central strand of floccose hyphae with inflated cells 8-12 (16) µ broad, subparallel; walls thin smooth and yellow to pale tawny in KOH; subhymenium of gelatinous narrow hyaline hyphae somewhat interwoven. Pileus cutis a gelatinous layer of yellowish hyphae with smooth to asperulate walls, hyphae 2.5-5 µ diam.; hypodermium in KOH strongly ochraceous to pale rusty brown, hyphae smooth to asperulate, cells 5-12 µ diam. Context of greatly inflated hyphae with smooth ochraceous walls, non-gelatinous. All hyphae inamyloid but with a distinctly reddish tone. Clamp connections present.

Habit, Habitat, and Distribution: Subcaespitose around elm and on soil with chips etc. mixed in it, Nov. 5, 1960, near Sharon Hollow (Manchester), Michigan, Smith 63406 type, and 72896, 20896; also Bartelli 2334.

Observations: This is a white to pallid to yellow species with veil material present on the cap in varying amounts. The marked change in color from youth to old age is quite deceiving. For further comment see var. robusta.