Thallus immersed. Photobiont: . Apothecia 1.7-3.0 mm high, 15-32 times as high as width of stalk. Stalk 0.08-0.13 mm diam., brown to reddish-brown in lower part, yellow in upper part. Uppermost part often with a yellow to white pruina. Stalks of young apothecia bright yellow, consisting of hyaline, non-sclerotized hyphae. Capitulum spherical, 0.35-0.52 mm diam. Excipulum forming a small collar at base of capitulum: collar 40-50 µm thick, of hyaline, not swollen, ± intricately branched hyphae. Lower side of excipulum covered in a dense pruina of yellow or white crystals. Hypothecium hyaline. Apothecial initials covered by a dense yellow pruina. Later this yellow pruina vanishes and instead the surface of the mazaedium is covered in a reddish-violet pruina. Mature apothecia have pale ochraceous mazaedia and less distinct pruina. Asci cylindrical to narrowly clavate, 20-25 × 2.8-3.7 µm, with uniseriate or in part somewhat overlapping spores. Asci formed singly, well-stalked. Ascospores spherical to broadly ellipsoid, hyaline, often with particles of pruina adhering to the surface and a minute, warty ornamentation of the wall. Spherical spores 3.2-4.1 µm diam. Chemistry: No secondary substances. The yellow pruina of apothecia is K-. The violet-red pruina dissolves in K and a precipitate of plate-like, violet-red crystals is formed.