Global occurrence: Eurasia – Europe | Americas – North America (incl Mexico) | Arctic.  Substrate: rock – calcareous, calciferous, basic | rock, stones, pebbles – unspecified.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: crustose (crustaceous) – endosubstratal, inconspicuous, immersed | crustose (crustaceous) – episubstratal – unspecified; thallus: continuous, diffuse, effuse; [th] upper surface: grey(ish); [th marginal and upper surface] specific structures: absent.  Ascomata: absent | present; ascoma: perithecial, perithecioid – hymenial; ascoma [mm]: (min) 0.2 (low) 0.28 (high) 0.4; ascoma: immersed, innate; [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: black(ish) | brown(ish) (if pale: fawn, tan; if mid: cinnamon); [ascm] paraphyses/-oids: absent.  Asci: fissitunicate – verrucarialean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): absent.  Ascospores: (min) 1.0(median) 2.0 (max) 4.0; [asp] shape: ellipsoidal | narrowly ellipsoidal; [asp] length [µm]: (min) 33.0 (low) 41.0(median) 45.0 (high) 49.0 (max) 88.0; [asp] width [µm]: (min) 17.0 (low) 19.0(median) 20.9 (high) 23.0 (max) 28.0; [asp] septa: present; [asp] septa: muriformly septate – muriform, submuriform; [asp] pigmentation: hyaline, colourless.  Secondary metabolites: absent.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.