The North American Species of Pholiota
88. Pholiota subvelutina sp. nov.
Illustrations: Text figs. 179-180.
Pileus 6-12 cm latus, laete luteus, udus. Lamellae laete luteae, subdistantes. Stipes 8-10 cm longus, 8-17 mm crassus, sursum luteus, deorsum sordide brunneus. Sporae 7-10 x 4-5. µ. Pleurocystidia desunt. Velum hyphorum crassotunicatum. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Florence, Ore., 22 Nov. 1934, Smith 3590.
Pileus 6-12 cm broad, convex to plane or the disc somewhat depressed, in age the margin elevated, surface with patches of converging fibrils particularly near the margin, glabrescent, viscid, "antimony-yellow" to "yellow-ochre," becoming darker ("cinnamon-brown") on the disc, margin faintly striate when moist, opaque after losing moisture. Context rather thin, tapering gradually to the margin, watery yellow, rather pliant; odor faintly fragrant, taste none.
Lamellae adnate or slightly adnexed, bright yellow, soon rusty (near ochraceous-tawny), narrow, subdistant to close, edges even.
Stipe 8-10 cm long, 8-17 mm thick, yellow above, dark sordid-brown below, appressed-fibrillose to subvelutinous, striate up to the fibrillose ring, equal or apex flattened, base clavate-enlarged.
Spores (7) 8-10 x 4-5 µ, smooth, germ pore at apex evident but apex not truncate; shape in face view ovate to subelliptic, in profile more or less distinctly inequilateral varying toward elliptic, apiculus small and inconspicuous; color in KOH golden-fulvous to fulvous, in Melzer's reagent distinctly tawny red (somewhat dextrinoid); wall about 0.3 µ thick.
Basidia 4-spored, 22-30 x 6.5-8 µ, subclavate to utriform, yellowish in KOH and in Melzer's reagent. Pleurocystidia none. Cheilocystidia 25-38 x 6.5-10 µ irregularly clavate or apex with one or more apical to sublateral protuberances, utriform or fusoid-ventricose to inflated-pedicellate, walls thin but in some cells (of all types) with pale cinnamon walls as revived in KOH. Caulocystidia none.
Gill trama of floccose hyphae, cells broad (to 15 µ) and greatly elongated; walls thin, ochraceous to pallid in KOH, smooth; subhymenium a thin subcellular (cut ends of hyphae?) non-gelatinous layer pale yellow to pallid in KOH. Pileus cutis with 3 distinct features: 1) over the surface occurs a thin wheft of interwoven non-gelatinous hyphae 3-5 µ diam. with walls thin to slightly thickened (±0.3 µ) and bright rusty brown in KOH, in Melzer's reagent merely yellowish. 2) a thick pellicle of gelatinous hyphae (their outline indistinct), yellowish, often encrusted, and 2-4 µ diam., the layer yellowish in KOH. 3) the hypodermial zone of compactly arranged ochraceous to ochraceous-rusty hyphae with walls non-gelatinous and smooth to encrusted. Context hyphae interwoven, the cells inflated; with smooth, ochraceous to paler, thin to slightly thickened walls. Surface of stipe with a dense covering of brown slender thick-walled hyphae with frequent clamps. All hyphae inamyloid.
Habit, Habitat, and Distribution: Caespitose or subcaespitose, on rotten log, Oregon, November, Smith 3590, type.
Observations: This is a moderately large fungus, with a fibrillose-subscaly, yellow pileus, with a slight fragrance, narrow gills, and large, yellowish, subvelutinous stipe which is clavate below. The colored thick-walled fibrils on the stipe are most unusual.