Elixia flexella (Ach.) Lumbsch

Thallus immersed or, if surficial, then very thin and inconspicuous, whitish or brownish grey and appearing as few, scattered granules, containing a trebouxioid alga; apothecia glossy, jet-black, distinctly thin, with a thin but prominent and persistent rim, round, or elliptical with a slit-like disc when young, but enlarging and sometimes gaping when mature, often developing three or four corners in the rim and thus triangular or square; exciple dark brown throughout as seen in LM; hymenium 35-45  µ high, of mostly unbranched paraphyses, the tips surrounded by a dark brown pigment; hypothecium colourless; asci thin-walled, slightly thickened at the tip, the thickening IKI+ blue; spores 8 per ascus, simple, colourless, elliptic, 4-8 × 2-4  µ.

Reactions: All spot tests negative.

Contents: No known lichen substances.

Habitat: On conifer wood, usually in the upper portions of the winter snowpack. All forested elevations.

Similar Species: No other crust lichen has thin, glossy, jet-black apothecia that fold into triangles or squares. Xylographa parallela (known from upper elevation forests outside the study area), has elongated apothecia with a slit-like disc, but lacks the gloss and is not quite jet-black, and the exciple interior is colourless.

Specimens: Björk 12890.

Local Status: Rare.