Summary: Ciboria caucus forms brown cups with stems, growing on fallen catkins of Populus. Hansen, L.(1) give C. amentacea (Balb.) Fuckel as a synonym of this species.
Microscopic: spores 9-10 x 5-6 microns, elliptic or somewhat elliptic, colorless; asci 8-spored, reaching 130 x 9 microns, cylindric-clavate, (Seaver), spores 7.5-10(11.5) x 4.5-6 microns (Hansen)
Notes: It is from found NY to OR and MB, as well as in Europe, (Seaver), and according to Kanouse from WA. There is collection from BC at the Pacific Forestry Centre.
Habitat and Range
SIMILAR SPECIES
Ciboria amentacea is similar if not a synonym, but grows on alder and willow.
Habitat
arising from mummified sclerotium in fallen catkins of Populus tremuloides and Salix, (Seaver), on catkins of Populus, Salix, and Alnus, exceptionally Corylus, fruiting in spring and early summer, (Hansen)