Upon further review, it appears to me that Alder Tongue Gall in the western US is Taphrina occidentalis. T. alni appears to be a European species; T.robinsoniana is a similar species in the eastern US. See https://www.researchgate.net/publication/43270414_New_records_for_powdery_mildews_and_Taphrina_species_in_Idaho_and_Washington and included references.
Todd Ramsden
2018-08-00
2018/08/02 9:07 AM PDT
United States of America, California, Plumas County, CA, USA