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

Summary:
Features include twisted, long, tongue-like outgrowths on female alder catkins that are yellowish green becoming orange, red, or purplish, and dry brown. Taphrina occidentalis has been known under the name Taphrina alni which is a European species (that has been found in Alaska). The description is from Beug(3) except where noted. T. occidentalis is common.

Distribution includes western North America. There is a collection by O. Ceska from BC under the name Taphrina alni at the University of British Columbia.

Fruiting body:
"produces a hypertrophic condition of the bract, resulting in long, twisted tongue-like outgrowths that are initially yellowish green, later becoming yellowish red, red or purplish, and drying brown"

Microscopic:
spores 2-6 x 1.5-4 microns, elliptic; asci 35-55 x 10-20 microns; basal cells 8-17 x 12-22 microns