Slideshow image
Dermatocarpon deminuens Vain.
Family: Verrucariaceae
Dermatocarpon deminuens image

Global occurrence: Eurasia – Europe | Arctic.  Substrate: rock, stones, pebbles – unspecified.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: peltate, umbilicate | foliose (foliaceous), leaf-like; continuous, diffuse, effuse; [th] upper surface: grey(ish) | grey(ish) brown; [th upper surface]: epruinose | pruinose; [th upper surface] pruina: scarce, sparse, fine | dense; [th marginal and upper surface] specific structures: absent; [th] lower surface: brown(ish) (if pale: fawn, tan; if mid: cinnamon); [th lower surface] specific structures: absent | present; [th lower surface] rhizines, rhizoid structures: absent; [th] medulla amyloidity: absent.  Ascomata: absent | present; ascoma: perithecial, perithecioid – hymenial; ascoma: immersed, innate; [ascm] paraphyses/-oids: absent.  Asci: fissitunicate – verrucarialean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): absent.  Ascospores: (median) 8.0; [asp] shape: ellipsoidal; [asp] length [µm]: (min) 14.0 (low) 16.0 (high) 22.0 (max) 25.0; [asp] width [µm]: (min) 5.5 (low) 6.5 (high) 8.5 (max) 9.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent.  Secondary metabolites: absent.  Primary photobiont:  present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.