The North American Species of Crepidotus

14. Crepidotus mollis var. cystidiosus var. nov.

Illustrations: Figs. 51, 52, 53.

Pileus (1)3-7 cm latus, sessilis, "tawny" fibrilloso-squamulosus, paene melleus, viscidus, striatulatus. Lamellae "tilleul buff” juvenes deinde "wood brown," latae, confertae. Sporae 8-10 x 5-6.5 (7) µ ellipsoideae demum ovoideae, planae. Basidia 26 -35 x 6-9(10) µ, tetraspora. Pleurocystidia 47-52 x 5-6 µ; cheilocystidia hymenialia: 34-41 x 2-8 µ, tramalia: 52-72 x 6-10 µ. Cuticula gelatinosa, gerens brunnearum incrustatarum hypharum fasciculos. Fibulae desunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Lake Quinault, Washington, May 17, 1939, A. H. Smith 13455.

Pileus (1.0) 3-7 cm broad, sessile, conchate, becoming dimidiate, margin at first inrolled but finally spreading, the surface covered by small "tawny" fibrillose squamules, at maturity the context showing toward the margin between the squamules near "honey yellow," in age dingy and nearly glabrous, at first not viscid, at maturity distinctly viscid, pellicle adnate, margin finally striatulate. Context "olive buff" when moist, 2.5 mm or more thick, rubbery; odor and taste none.

Lamellae "tilleul buff" when young, becoming "wood brown", broad (5-7 mm), close to crowded, radiating from a lateral point, 3-5 tiers of lamellae, soft and collapsing against one another.

Stipe none; area of attachment broad and faintly tawny-pubescent. Spores 8-10 x 5-6.5 (7) µ, ellipsoid to ovoid in face-view, slightly inequilateral in profile, smooth, wall thickened somewhat, dull tawny in KOH. Basidia 26-35 x 6-9 (10) µ, 4-spored. Pleurocystidia at times found chiefly on the lower half of the gill, 47-52 x 5-6 µ, subcylindric or subfusoid, at times with a slight neck; cheilocystidia of two general types: (a) regular, hymenial type, cylindric to flask-shaped, 34-41 x 2-8 µ; (b) tramal type, 52-72 x 6-10 µ, clavate, cylindric, at times forked, or branched at the apex. Gill trama irregularly subparallel, hyphae 6-12 µ broad. Subhymenium of narrow, parallel hyphae. Pileus trama interwoven. Cuticle a thick (200-350 µ) gelatinous zone of narrow interwoven hyphae, surmounted by bundles of brown, septate, incrusted hyphae forming scales. Hypodermium rather distinct. Clamp connections none.

Habit, Habitat, and Distribution: On Alnus, Washington, May.

Material Studied: WASHINGTON: Smith 13455, type, from Lake Quinault, May 17, 1939.

Observations: This differs from C. mollis var. mollis in the presence of pleurocystidia, and the “tilleul buff” gills when young.