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Gyalidea rivularis (Eitner) J. Novak & Tobol.
Family: Gomphillaceae
[Gyalecta rivularis Eitner,  more]
Gyalidea rivularis image

Global occurrence: Eurasia – Europe.  Substrate: rock – siliceous, siliciferous, acidic.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: crustose (crustaceous) – episubstratal – unspecified; continuous, diffuse, effuse | cracked, fissured, fractured, rimose; [th] upper surface: yellow(ish) brown; [th marginal and upper surface] specific structures: absent; [th] morphol substructures (eg areoles, lobes, branches) upper surface: smooth, plane | cracked, fissured, fractured, rimulose, subrimose.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 0.1 (high) 0.2; [ascm, if apoth] disc, mazaedium: brown(ish) (if pale: fawn, tan; if mid: cinnamon); [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: black(ish); [ascm] paraphyses/-oids: present.  Asci: unitunicate; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): absent.  Ascospores: (median) 8.0; [asp] length [µm]: (low) 16.0 (high) 18.0; [asp] width [µm]: (low) 6.0 (high) 7.0; [asp] septa: present, muriformly septate – muriform, submuriform; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: thick, distincly halonate.  Secondary metabolites: absent.  Primary photobiont:n present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.