The North American Species of Pholiota

45. Pholiota bridgii sp. nov.

Illustrations: Text figs. 141-143.

Pileus 1-4 cm latus, convexus vel planus, glaber, udus, sordide cinnamomeus deinde argillaceus. Lamellae confertae, adnatae, secedentes, angustae vel medio-latae, sordide cinnamoneae. Stipes 2-6 cm longus, 1.5 -3.5 mm crassus, caespitosus, sursum atro-brunnescens. Velum fibrillosum. Sporae 6-7.5 (8) x 3.8-4.2 (4.5) µ, leves truncatae. Cheilocystidia 28-42 x 7-11 µ, versiformia. Specimen typicum in Herb. Univ. of Mich. conservatum est; legit prope Mt. Shasta, Calif., 11 July 1963, Wm. Bridge Cooke 34315.

Pileus 1-4 cm broad, broadly convex, expanding to nearly plane, surface glabrous, hygrophanous, brown when moist, fading to pale dingy clay-color, not viscid.

Lamellae close, adnate-seceding, narrow to moderately broad, dull cinnamon when mature.

Stipe 2-6 cm long, 1.5-3.5 mm thick, caespitose, base coated with appressed whitish mycelium, becoming very dark brown from base up to apex; cortina scanty, apex pruinose.

Spore deposit near clay color. Spores 6-7.5 (8) x 3.8-4.2 (4.5) µ, smooth, apex somewhat truncate from the apical pore; shape in face view narrowly ovate to suboblong, in profile slightly inequilateral, wall about 0.25 µ thick; in KOH the walls dull cinnamon, in Melzer's reagent about the same color as in KOH or paler.

Basidia 18-23 x 5-7 µ, 4-spored, hyaline in KOH, narrowly clavate. Pleurocystidia none. Cheilocystidia abundant, 28-42 x 7-11 µ subcylindric to subfusoid or somewhat fusoid-ventricose, apex subacute to obtuse, wall smooth, thin, hyaline or near base slightly cinnamon. Caulocystidia versiform, 30-56 x (7) 9-16 µ, subcylindric with various constrictions, fusoid-ventricose with narrow neck and acute apex or subclavate, wall often thickened to 0.5-1.2, and often colored in pedicel.

Gill trama as revived in KOH cellular with cells 10-25 µ diam. having rusty brown walls thickened to 0.5-1.5 µ and "double" in optical section, subhymenium also of dark cinnamon cells but narrow and wall often finely encrusted. Pileus cuticle with an epicutis of hyphae 2-5 µ diam., with minutely asperulate walls and not gelatinous. Hypodermial zone of greatly inflated hyphal cells (to 20 µ) with rusty brown thickened walls. Context of greatly inflated hyphal cells also thick-walled (0.5-1.5 µ). Clamp connections present. All hyphae inamyloid.

Habit, Habitat, and Distribution: Caespitose on a rotten Abies concolor log, Wagon Camp, Mt. Shasta, California, July 11, 1963. William Bridge Cooke 34315, type; elevation 5700 ft.

Observations: This species differs from P. obscura in smaller spores, large thick-walled cells comprising the gill trama, close narrow gills at first, and lack of a gelatinous pellicle on the pileus. It is closest to P. marginella in most features but differs in the much more greatly inflated cells of the gill trama and the darker color of the stipe when fresh. Also, in P. bridgii there is a distinct colored hypodermial region of hyphal cells with slightly thickened walls.