The North American Species of Pholiota

177. Pholiota coloradensis sp. nov.

Illustrations: Text figs. 393-394; 395.

Pileus 5-6 cm latus, campanulatus, glaber, viscidus, aurantiacus ("ochraceous-orange"), ad marginem albofibrillosus. Contextus albus. Lamellae subdecurrentes, angustae pallide griseo-olivaceae demum subfulvae. Stipes 5-6 cm longus, 9-10 mm crassus, solidus, albidus, deorsum demum subfulvus. Sporae 6-7.5 x 4-4.5 µ. Pleurocystidia 45-65 x 9-15 µ, utriformia, tenuitunicata. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Tolland, Colo. 12 Sept. 1920. C. H. Kauffman.

Pileus 5-6 cm broad, campanulate-convex, obtuse when young, broadly umbonate in age, glabrous, viscid, pale orange ("ochraceous-orange") when fresh (all ochraceous as dried), in age at times spotted from the gluten. Margin whitish from veil remnants disposed along it. Context white to whitish, thick, scissile.

Lamellae adnexed becoming subdecurrent, rather narrow, close to crowded, almost "dark olive-buff" then "Isabella-color" to "tawny-olive," edges entire, concolor.

Stipe 5-6 cm long, 9-10 mm thick, solid, persistently fibrous-stuffed, white at first, very thinly peronate to the annular zone, concentrically arranged shreds or patches of veil material lower down, becoming rusty brown in base. Veil gelatinous outside—fibrillose to interior.

Spores 6-7.5 x 4-4.5 µ pale tawny in KOH and about the same in Melzer's reagent, smooth, apical pore very minute, in face view elliptic to ovate; in profile mostly obscurely inequilateral to subovate, apiculus indistinct.

Basidia 18-23 x 5-6.5 µ 4-spored, clavate, yellowish in KOH and Melzer's reagent. Pleurocystidia 45-65 x 9-15µ, subcylindric to utriform, apex broadly rounded, wall thin smooth and hyaline; content homogeneous ochraceous in KOH and slowly bleaching. Cheilocystidia similar to pleurocystidia or more obese.

Gill trama typical of P. lubrica group. Pileus cutis a thick pellicle of interwoven narrow (2-3 µ) hyaline to yellowish hyphae with minutely asperulate walls; hypodermial zone of orange-rusty incrusted broader hyphae and context hyphae 6-15 µ ± broad, smooth, thin-walled and nearly hyaline. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: On humus under spruce, Tolland, Colorado. 9500 ft. Sept. 12, 1910. C. H. Kauffman, type.

Observations: This species was identified by Kauffman as Flammula lubrica but the broadly rounded pleurocystidia do not check with European material. It is close to P. tetonensis in cystidial features. The colors approach those shown for Agaricus (Flammula) lubricus in Fries' Icones.