Summary:
Features include 1) a red-brown to chocolate brown cap that is paler toward the margin, 2) broad, notched, cream to brown gills with white-fringed edges, 3) a white-fibrillose stem that becomes brown, 4) an association with willow, 5) very large spores on 2-spored basidia, 6) clavate to capitate cheilocystidia, and 7) a cellular cap cuticle with cystidioid outgrowths.

Cap:
1-2.2(3)cm across, convex to bell-shaped when young, later flat with an obtuse to prominent umbo, "margin even, acute, not incurved"; reddish brown, paler to beige toward margin, center dark red-brown to black-brown; "smooth, dull, sometimes furfuraceous to granulose", translucent-striate up to 2/3 of the distance to center when moist, (Breitenbach), 1-4cm across, dark reddish brown, umber, or chocolate, (Hansen, L.), 0.8-5.5cm across, bell-shaped to convex; fairly dark red-brown to umber-brown, when young almost black-brown, when dry reddish-cocoa-brown; matte, (Moser), reddish brown to chocolate-colored (Trudell)

Flesh:
thin; whitish to gray-brown, (Breitenbach)

Gills:
"notched and narrowly attached to almost free", 26-34 reaching stem, 3 subgills between neighboring gills, gills broad; cream when young, later light pink-brown to ocher brown; edge white-ciliate, (Breitenbach)

Stem:
2-4(5)cm x 0.15-0.35(0.5)cm, cylindric, "solid to hollow, flexible"; longitudinally white-fibrillose on a cream background when young, later becoming bald and browning from the base up, apex white-pruinose, (Breitenbach), 3-7cm x 0.15-0.5cm, reddish brown, "with a fine white coating disappearing when old or by handling", (Hansen, L.), 2.5-7cm x 0.15-0.8cm, white-silky, when old +/- darker brown, (Moser)

Odor:
weakly herbaceous to radish-like (Breitenbach)

Taste:
mild to somewhat astringent (Breitenbach), none or slightly bitterish (Moser)

Microscopic spores:
spores 12.6-20.7 x 6.8-10.5 microns, almond-shaped to lemon-shaped, "weakly verrucose, smooth apically, with a tendency for the perispore to detach, light yellow"; basidia 2-spored, 28-35 x 8-10 microns, fusiform to clavate, without basal clamp connection; pleurocystidia not seen, cheilocystidia 40-70 x 11-20 microns, clavate to capitate; cap cuticle of more or less spherical cells 15-30 microns across, "those in the uppermost layer with clavate to cylindrical outgrowths", colorless, septa without clamp connections, (Breitenbach), spores 13-20 x 6-8 microns; basidia 2-spored; cheilocystidia 40-80 x 8-20 microns, clavate, long-stalked, (Hansen, L.), spores (12)13-20(22) x 5.5-8.5(9) microns; basidia 2-spored; cap cuticle "cellular with roundish, spindle-shaped and flask-shaped elements", (Moser)

Spore deposit:
olive-brown (Breitenbach)

Notes:
It has been found in the Pacific Northwest (Trudell(4)), and Europe (Breitenbach). It was reported by A and O Ceska from BC.

EDIBILITY

Synonyms and Alternate Names:
Alnicola salicis (P.D. Orton) Bon