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

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.

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).

Upper surface:
fruitbodies "at first rounded, becoming expanding and subdiscoid, with a mealy, brown covering", reaching about 0.05-0.1cm across, spore-bearing surface flat or nearly so, yellowish to dark brownish black, (Seaver)

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)