Description: Thallus crustose, very thinly episubstratic, subgelatinous when wet, minutely granulose, greenish grey to dark green, usually intermixed with algal films. Apothecia short-lived, semi-immersed to broadly sessile, whitish or pale waxy yellow when dry, translucent when moist, round, 0.1-0.2 mm across, with a concave to finally flat disc, and a scarcely raised, moderately thick, entire proper margin. Proper exciple colourless, laterally 40-50 µm wide, of conglutinated, parallel hyphae: epithecium indistinct, colourless; hymenium colourless, 60-65(-70) µm high, I+ yellowish, K/I-; paraphyses dense, slender, indistinctly septate, simple or forked, 0.5-0.8 µm thick, irregularly broadened at tips; hypothecium very thin, colourless. Asci 8-spored, long-cylindrical, thin-walled, the upper part with a distinct, K/I- apical dome penetrated by a long, narrow tube extending from the endoascus. Ascospores 3-septate, hyaline, fusiform, 9-15 x 4-7 µm, with very thin walls and septa. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: without lichen substances.
Note: a boreal-montane, ephemeral lichen, mostly found on horizontal surfaces of stumps and logs, mostly of conifers, with optimum in the subalpine belt. Easily overlooked, it might be more widespread in the Alps.