Slideshow image
Melanohalea exasperata (De Not.) O. Blanco et al.
Family: Parmeliaceae
[Imbricaria aspera (A. Massal.) Körb.,  more]
Melanohalea exasperata image

Global occurrence: Africa (incl Madagascar) | Eurasia – Asia Extratropical | Eurasia – Europe | Americas – North America (incl Mexico) | Eurasia – Asia Tropical | Arctic.  Substrate: wood – dead, living | bark, cork, plant surface – trunks, branches, twigs | rock – siliceous, siliciferous, acidic | rock, stones, pebbles – unspecified.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: foliose (foliaceous), leaf-like; continuous, diffuse, effuse; [th] upper surface: brown(ish) green (olivaceous, olive green) | black(ish) brown | green(ish) brown (olive brown) | red(dish) brown (if pale: orange brown); [th upper surface]: epruinose; [th marginal and upper surface] specific structures: absent | present; [th margin] cilia, cilioid structures: absent; [th upper surface] isidia, isidioid structures: absent | present; [th upper surface] soredia, soralia, soralioid structures: absent; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (low) 1.0 (high) 4.0 (max) 6.0; [th] morphol substructures (eg areoles, squamules): distantly discontiguous; [th] morphol substructures (eg areoles, lobes, branches) upper surface: granulose, granular | verrucose, warted | pseudocyphellate, with pseudocyphellae; [th] morphol substructures (eg lobes, branches): subdichotomous | irregular; [th] lower surface: black(ish) | brown(ish) (if pale: fawn, tan; if mid: cinnamon); [th lower surface] specific structures: present; [th lower surface] rhizines, rhizoid structures: present; [th lower surface] rhizines, rhizinoid structures: unbranched, simple.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (median) 6.0 (max) 8.0; ascoma: sessile, superficial | subpedicellate, substipitate, subpedunculate, substalked; [ascm, if apoth] disc, mazaedium: concave | plane, flat, flattened, expanded; [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: black(ish) brown | green(ish) brown (olive brown) | red(dish) brown (if pale: orange brown); [ascm, if apoth] margin excipular photobionts: present; [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: hyaline, colourless; [ascm] paraphyses/-oids: present.  Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): present; [asc] tholus amyloidity pattern: amyloid with widening axial body towards the apex (= Lecanora-, Parmelia-, Rinodina-types etc).  Ascospores: (median) 8.0; [asp] shape: broadly ellipsoidal | ellipsoidal; [asp] length [µm]: (low) 8.5 (high) 12.0; [asp] width [µm]: (low) 5.0 (high) 7.0; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless; [asp] perispore, epispore: not apparent.  Conidiomata: absent | present.  Conidia: fusiform | acerose (needle-shaped); [co] length [µm]: (low) 7.0 (high) 8.0.  Secondary metabolites: absent.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.