Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Thallus: entirely immersed or very sparse surface: apparently white or whitish green photobiont: a cyanobacterium, Hyella; cells: orange Perithecia: to 0.2-0.6 (-1.5) mm diam. [on soft chalk, half-immersed by erosion of the substratum, to 1 mm on limestone and then subsessile (even on hard rock)]; black; ostioles not prominent involucrellum: brown-black, extending part way down over the exciple and spreading; exciple: hyaline to pale brown, to 200 µm diam. hamathecium: much-branched paraphysoid network, somewhat persistent asci: subcylindrical to cylindrical, c. 8-spored ascospores: narrowly ovoid, hyaline, 1-septate, cells unequal in size, 12-20 (-24) x 5-7 (-10) µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on calcareous rocks amongst seaweeds in the sublittoral zone, especially ridges uncolonized by barnacles, and on shells (barnacles and limpets) World distribution: Europe, west coast in North America, and New Zealand Sonoran distribution: coastal California [reported from central part; may also occur in southern part]. Notes: In many treatments prior to 1992 this species was treated as a synonym of C. halodytes. Santesson (1992) distinguishes the species on the basis of the immersed thallus. However, C. sublitoralis has a whitish thallus and larger, more prominent perithecia. This species is not yet reported from the area, but it is likely to occur.

Global occurrence: Oceania – Australasia | 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; [th] upper surface: white(ish) | white(ish) green; [th marginal and upper surface] specific structures: absent.  Ascomata: absent | present; ascoma: perithecial, perithecioid – hymenial; ascoma [mm]: (min) 0.15 (low) 0.2 (high) 0.6 (max) 1.5; ascoma: subsessile, subimmersed, adnate, semi-immersed, emergent | sessile, superficial; [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: black(ish); [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: hyaline, colourless; [ascm] paraphyses/-oids: present.  Asci: fissitunicate – bitunicate; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): absent.  Ascospores: (median) 8.0; [asp] shape: ovoid, ovate; [asp] length [µm]: (min) 12.0 (low) 15.0 (high) 20.0 (max) 25.0; [asp] width [µm]: (low) 5.0 (high) 7.0 (max) 10.0; [asp] septa: present, transversely septate; [asp] transversal septa: (median) 1.0; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent.  Conidiomata: absent | present.  Secondary metabolites: absent.  Primary photobiont: present, cyanobacterial.  Secondary photobionts (eg in cephalodia): absent.