Summary:
Features include tiny, reddish brown to blackish, urceolate cups, with grayish to whitish spore-bearing surface, the margin becoming fringed, hard consistency, little or no stem, growth on willow, and microscopic characters.

Microscopic:
spores (40)55-80(90) x (1.5)2.0-3.5(4.0) microns, filiform [thread-like], "more or less curved to nearly straight, pointed at ends", colorless, mostly 5-septate to 7-(9-)septate, fasciculate to somewhat interwoven in the ascus; asci 8-spored, (90)105-135(150) x (8)9-12(14) microns, cylindric to cylindric-clavate, tapering in lower part to a slender stem, pore blue with iodine; paraphyses 1.5-2.5 microns wide, filiform, colorless, septate, simple or branched, "the tips not or very slightly swollen, not forming an epithecium"; conidia (18)20-30(36) x (2.0)2.5-3.5 microns, "elongate-fusiform, straight or curved", colorless, mostly 3-septate; conidiophores about 6-25 x 2-2.5 microns or longer, "cylindric-subulate, septate, simple or branched"; microconidia 3.0-4.0(5.0) x 2.0-3.0 microns, elliptic, colorless, 1-celled

Notes:
There are several collections from BC at the Pacific Forestry Center, one determined by J. Groves in 1964. Collections were examined from ON, SK, CO, NY, Finland, Germany, and Sweden, (Groves(3)).