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

Summary:
Pulvinula laeterubra produces minute, pale yellow discs on mossy burnt ground, and is characterized by microscopic characters. The description is derived from Seaver(1).

It is found in BC and AB, (Larsen).

Upper surface:
scarcely exceeding 0.1cm wide, at first spherical or nearly so, becoming disc-shaped or nearly so; pale yellow

Underside:
pale yellow, similar in color to upper surface

Microscopic:
spores round, never exceeding 10 microns in diameter and often smaller, smooth, colorless, granular within but not containing conspicuous oil drops, at first partly biseriate or irregularly crowded, finally becoming uniseriate; asci reaching 150-175 x 12-14 microns; paraphyses filiform, 1.5-2 microns wide, slightly thickened in upper part and strongly curved at tip, sparingly branched, filled with colorless granules