The North American Species of Pholiota

174. Pholiota vialis (Murr.) comb. nov.

Flammula vialis Murrill, Mycologia 4: 262. 1912.
Gymnopilus vialis Murrill, Mycologia 4: 255. 1912.

Illustrations: Text fig. 384-386.

Pileus 5 cm broad, convex to expanded, at length depressed, dark flavo-luteous with bay center or the entire surface bay, splitting radially at the margin, viscid, glabrous, smooth, at length rimose.

Lamellae adnate, citrinous to ferruginous-fulvous, ventricose, broad, rather crowded.

Stipe 5 cm long, 10-15 mm thick, citrinous, equal or inflated, solid or hollow, fibrillose, especially at the top where a slight trace of the fugacious veil remains.

Spores (6) 7-9 x 4-4.5 (5) µ, smooth, apical pore minute; shape in face view oblong to elliptic, more rarely ovate, in profile mostly somewhat inequilateral; color revived in KOH, dull cinnamon-brown, in Melzer's reagent paler; wall about 0.3 µ thick.

Basidia 23-30 x 5-7 µ, 2- and 4-spored, clavate, yellowish in KOH and in Melzer's reagent. Pleurocystidia 36-75 x 7-15 µ, fusoid-ventricose varying (rarely) toward utriform or subclavate, wall thin smooth and hyaline, content amber-brown to yellow and on standing in KOH gradually becoming hyaline, homogeneous. Cheilocystidia 33-52 x 7-12 µ, subfusoid, utriform, or fusoid-ventricose, smooth, thin-walled, walls yellowish in some, content soon homogeneous (in KOH). Caulocystidia none found.

Gill trama with a central floccose area of somewhat interwoven hyphae, cells elongate and up to 15 µ broad, walls thin and smooth, yellowish to hyaline in KOH; subhymenium a distinct gelatinous layer of somewhat interwoven hyphae 2-3 µ broad. Pileus cutis a well developed pellicle of interwoven narrow (1.5-3 µ) hyaline to ochraceous hyphae with smooth walls but toward hypodermium some with tawny incrustations; hypodermial region of rusty fulvous floccose encrusted hyphae 5-15 µ diam. Context hyphae interwoven, cells inflated, walls thin smooth and yellowish to hyaline. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: On wood, Oregon, November. Type studied.

Observations: We recognize this species with great reluctance, but if caulocystidia really are absent this would distinguish it from European specimens of P. spumosa we have studied. Also, the utriform cheilocystidia mixed in with the normal type for the P. spumosa group may be an additional character. In fact the presence of utriform cheilocystidia indicates a connection to P. graveolens but for P. vialis we have no data on the odor. The bay colored pileus disc would seem to exclude P. spumosa, but the dried basidiocarps are not too convincing. They resemble those of P. spumosa. P. piceina differs in its clear bright yellow pileus as dried. No thick-walled pleurocystidia were found.