E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include a small brown basidiomycete fruitbody that is deeply tubular to cup-shaped with a cream inner spore-bearing surface, external hairs that usually exhibit spiral coiling, growth on hardwood often in clusters, and microscopic characters. Var. occidentalis differs in having spores 9-11 x 3.5-4.5 microns. Var. oreganus differs in having spores 9-13 x 5-7.5 microns.

Var. fasciculata is found in BC, OR, and also MB, NF, NS, ON, PQ, YT, AL, CO, DE, GA, IN, LA, MA, MD, ME, MI, MO, NC, NH, NJ, NY, PA, RI, SC, VA, VT, WI, and WY, var. occidentalis is found in WA, OR, ID, CA, and CO, and var. oreganus is found in WA and OR, (Ginns).

Upper surface:
0.2-0.5cm, shallow cup-shaped, margin straight to more or less undulate [wavy], in robust specimens becoming split to somewhat fimbriate [fringed], when the stem is extended the cups are hanging; cream colored; smooth to weakly wrinkled in some older or larger specimens, (Cooke), up to 0.1cm in height and width as measured dried, produced in a pustule that breaks out from beneath the bark, deeply tubular-campanulate or horn-shaped; when dried with a pale yellowish or cream colored spore-bearing upper surface, similarly colored when fresh, (Reid)

Underside:
covered with hairs, zoned in older specimens, (Cooke), when dried snuff brown, when fresh similar in color, old weathered fruitbodies appear grayish; appearing minutely villose under a hand lens, old weathered fruitbodies may be somewhat lobed and grooved, (Reid)

Stem:
with a stem, but stem sometimes remaining within the lenticel, (Cooke), with a stem or without, fruitbodies toward the outside of a crowded colony become pushed to one side and frequently develop very distinct stems; "fruitbodies are separated from each other by the development of erect, brown subicular hyphae resembling the surface hairs" that clothe the fruitbody, (Reid)

Microscopic:
spores typically 7-9(10-11) x (1.5)2-3(3.5) microns, cylindric to allantoid [curved sausage-shaped], clamp connections common especially in subhymenial tissue and at base of basidia; hairs 275 x 3-4 microns, brown, thick-walled, smooth in lower part, "closely and finely granule incrusted on outer half to three-quarters of length, granules easily removed in mounting", with pointed, colorless, incrusted tips, straight to flexuous [wavy], curled, hooked or spiraled, (Cooke), spores 6.2-10.5 x 2-2.5 microns, narrowly subcylindric to slightly allantoid, colorless or pale brown, thin-walled; basidia 4-spored, up to 20.8 x 5.5 microns, clavate; cystidia absent; hairs up to 450 microns long and 3.5(4) microns wide, with distinctly thickened brown walls except for the tip part that is often thin-walled and colorless, toward the obtuse uninflated apex some hairs become wavy or coiled in a loose spiral, but this may be difficult to demonstrate, hairs usually narrow toward base and end in a clamped septum, they may develop occasional secondary septa; pustular base formed of hyphae up to 5 microns wide, irregularly kinked and branched, colorless, clamped; walls of similar hyphae 2.5-3 microns wide, more regularly arranged and parallel, (Reid)