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Rhizocarpon umbilicatum (Ramond) Flagey
Family: Rhizocarpaceae
[Diplotomma umbilicatum (Ramond) Jatta,  more]
Rhizocarpon umbilicatum image
Life habit: lichenized (mutualistic with algal photobionts) thallus: crustose (crustaceous) – episubstratal – unspecified thallus: cracked, fissured, fractured, rimose | compartimentized – areolate, squamulate [th] upper surface: grey(ish) | white(ish) | blue(ish) grey [th marginal and upper surface] specific structures: absent ascomata: absent | present ascoma: apothecial, apothecioid – hymenial ascoma [mm]: (median) 2.0 ascoma: subsessile, subimmersed, adnate, semi-immersed, emergent | sessile, superficial [ascm, if apoth] disc, mazaedium: black(ish) [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: black(ish) [ascm, if apoth] margin excipular photobionts: absent | present [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | black(ish) brown [ascm] paraphyses/-oids: present [ascm] epihymenium, epithecium: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | green(ish) black | green(ish) grey asci: lecanoralean [asc] tholus: thickened [asc] tholus amyloidity (iodine reaction): present [asc] tholus amyloidity pattern: with amyloid cap (= Icmadophila-, Lecidea-, Pertusaria-types etc) ascospores: (median) 8.0 [asp] shape: ellipsoidal [asp] length [µm]: (low) 18.0 (high) 28.0 [asp] width [µm]: (low) 10.0 (high) 16.0 [asp] septa: present [asp] septa: transversely septate | muriformly septate – muriform, submuriform [asp] transversal septa: (median) 3.0 [asp] pigmentation: pale brown | medium brown, brownish | dark brown [asp] perispore, epispore: thick, distincly halonate secondary metabolites: present secondary metabolites: stictic acid primary photobiont: present secondary photobionts (eg in cephalodia): absent primary photobiont: chlorophytaceous – trebouxiaceous, chlorococcoid.

substrate: rock – calcareous, calciferous, basic | rock, stones, pebbles – unspecified.