Summary:
Features include 1) a minute, disc-shaped fruiting body with a mealy brown covering and a flat, yellowish to brownish black upper spore-bearing surface, 2) growth on dogwood (Cornus), and 3) microscopic characters. Seaver''s illustrations appear to show 1-septate and 3-septate mature spores, and the granular coating on the upper surface.

Microscopic:
spores 28-34 x 10-13 microns, elliptic, irregularly crowded in the ascus; asci 8-spored, reaching a length of 120 microns and a width of 27 microns, clavate; paraphyses filiform [thread-like], slightly enlarged in upper part; accompanied by a Myxosporium that appears to be its conidial stage, the pycnospores 33-36 x 13-15 microns, elliptic and densely filled with granules, (Seaver)

Notes:
Pezicula corni is found in ID, CA to OR and ON, (Seaver). Collections from BC were deposited at Pacific Forestry Centre (determined by J. Groves).

Synonyms and Alternate Names:
Discina apiculata McKnight
Discina olympiana Kanouse