The North American Species of Pholiota

111. Pholiota abietis sp. nov.

Illustrations: Text figs. 233-236; pls. 53-54.

Pileus 4-9(15) cm latus, late convexus, glutinosus, squamosus lutteus, squamis fulvis. Contextus subluteus. Lamellae pallidae demum cinnamomeae, adnatae, latae, confertae. Stipes 8-12 cm longuts, 9-15 mm crassus, solidus, aequalis sed ad basin submarginatus, deorsum squamosus; squamis siccis. Sporae 5.5-7 (7.5) x 3.5-4 µ leves. Pleurocystidia: 1) 32-46 x 8-12 µ clavata vel mucronata, subbadia. 2) Chrysocystidia 26-42 x 6-12 µ. Caulocystidia (20) 30-70 x 6-12 (20) µ, versiformia. Specimen typicum in Herb. Univ. Mich. conservatum est; legit prope Joyce, Wash. 24 Sept. 1935. Smith 2585.

Pileus 4-9 (15) cm broad, broadly convex with an incurved margin, in age nearly plane, more rarely with an obtuse umbo, surface slimy-viscid and covered by appressed spot-like tawny-brown scales arranged in concentric rows and causing the predominant tawny-fulvous color, lemon-yellow between the scales and on margin, margin at first appendiculate with veil fragments. Context pliant, moderately thick, pale dull yellow, odor and taste mild.

Lamellae when young pallid brownish (not yellow), becoming a dull cinnamon and when dried rusty-fulvous, moderately broad, close, tapering toward the cap margin, adnate to slightly adnexed or rounded as they meet the stipe.

Stipe 8-12 cm long, 9-15 mm thick, solid, equal to a slightly enlarged base, silky-pruinose to glabrous above the veil line and more densely scaly as one progresses down from the line, the scales fibrillose and dry, veil leaving an evanescent zone near apex (never a distinct annulus), ground color yellowish over all and not distinctly darker over basal area.

Spore print rusty cinnamon. Spores 5.5-7 (7.5) x 3.5-4 (4.5) µ, smooth, apical pore distinct but apex not truly truncate; shape in face view oblong to elliptic or more rarely obscurely ovate, in profile elliptic or nearly so varying to obscurely inequilateral, near cinnamon-brown in KOH and not much different (paler) in Melzer's reagent.

Basidia 18-23 x 5.5-7 µ, 4-spored, narrowly clavate, hyaline to yellowish in KOH or Melzer's reagent. Pleurocystidia 32-46 x 8-12 µ, clavate to clavate-mucronate and filled with dark reddish brown contracted wrinkled content (as revived in either KOH or Melzer's reagent), in addition chrysocystidia 26-42 x 6-12 µ present with hyaline thin smooth walls and a refractive inclusion, these clavate, fusoid or clavate-mucronate. Cheilocystidia (23) 32-56 x (4) 6-9 (11) µ, versiform but mostly varying around narrowly fusoid-ventricose to subcylindric-capitate, more rarely clavate or enlarged part irregular in outline, walls thin smooth and hyaline in KOH or in a few slightly thickened (± 0.4 µ), hyaline (yellow to tawny if poorly dried), content typically hyaline and homogeneous. Caulocystidia numerous above veil line, (20) 30-70 x 6-12 (20) µ, elongate clavate, elongate-fusoid and of regular to irregular outline, filamentous-capitate with the capitellum lopsided at times, or fusoid-ventricose, walls hyaline to pale cinnamon and smooth to incrusted.

Gill trama of a central area of floccose hyphae subparallel and cells greatly elongated, 6-15 µ wide, walls hyaline and somewhat refractive as well as thickened slightly (showing as 2 double lines), smooth; subhymenium a gelatinous layer of closely packed hyaline hyphae 1.5-3 µ diam. Pileus cutis a thick gelatinous pellicle reddish in KOH, the hyphae 4-10 µ diam., appressed and walls gelatinizing, smooth to asperulate; hypodermial region not differentiated. Context hyphae yellowish to hyaline in KOH, smooth, walls thin, closely interwoven. Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: Caespitose-gregarious on Abies, dead trees, logs etc., Agate Beach, near Joyce Wash. Sept. 24, 1935. Smith 2585, type.

Observations: For years we have identified this species as P. squarroso-adiposa but Lange described the latter as having yellowish gills when young, and the stipe as having ferruginous-cinnamon scales. In ours the scales are not so dark colored and as dried the stipe is the same color over all, not darker below as in P. connata and as shown by Lange for P. intermedia (squarroso-adiposa). There is also the difference in habitat, one on conifer wood and the European species on that of Juglans, a deciduous species. In view of the fact that in North America there has been much confusion in the application of the names for taxa in this group we choose not to ignore the differences shown by American collections even though some may appear to be of minor importance. The spores in P. aurivella are larger but the stipe features of P. abietis remind one of that species.