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Biatora helvola (Korber) Hellbom
Family: Ramalinaceae
[Lecidea helvola (Körb.) Th. Fr.]
Biatora helvola image
Life habit: lichenized (mutualistic with algal photobionts) thallus: crustose (crustaceous) – endosubstratal, inconspicuous, immersed | crustose (crustaceous) – episubstratal – unspecified thallus: compartimentized – areolate, squamulate [th] upper surface: grey(ish) | green(ish) grey | white(ish) grey | grey(ish) green [th marginal and upper surface] specific structures: absent [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (low) 0.1 (high) 0.3 [th] morphol substructures (eg areoles, lobes, branches) upper surface: verrucose, warted ascomata: absent | present ascoma: apothecial, apothecioid – hymenial ascoma [mm]: (low) 0.3 (high) 0.5 (max) 0.8 ascoma: subsessile, subimmersed, adnate, semi-immersed, emergent | sessile, superficial [ascm, if apoth] disc, mazaedium: subconvex, slightly convex [ascm, if apoth] disc, mazaedium: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | yellow(ish) brown | red(dish) brown (if pale: orange brown) | yellow(ish) white (ivory, off-white, cream-coloured) [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: yellow(ish) (if dull: buff) | hyaline, colourless [ascm] paraphyses/-oids: present [ascm] epihymenium, epithecium: hyaline, colourless asci: lecanoralean [asc] tholus: thickened [asc] tholus amyloidity (iodine reaction): present [asc] tholus amyloidity pattern: amyloid with acuate axial body towards the apex (= Bacidia-, Buellia-, Ramalina-types etc) ascospores: (median) 8.0 [asp] shape: narrowly ellipsoidal [asp] length [µm]: (min) 8.5 (low) 10.2 (high) 14.2 (max) 17.5 [asp] width [µm]: (min) 3.0 (low) 3.4 (high) 4.5 (max) 5.0 [asp] septa: absent – spore lumen unilocular, monolocular | present [asp] septa: transversely septate [asp] transversal septa: (median) 0.0 (max) 1.0 [asp] pigmentation: hyaline, colourless [asp] perispore, epispore: not apparent secondary metabolites: present secondary metabolites: gyrophoric acid | lecanoric acid primary photobiont: present secondary photobionts (eg in cephalodia): absent primary photobiont: chlorophytaceous – trebouxiaceous, chlorococcoid.

substrate: bark, cork, plant surface – trunks, branches, twigs.
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus thin, verruculose or slightly so, gray-white or blue-white, lacking soredia; hypo-thallus indistinct. Apothecia small, to 0.5 mm, sometimes tuberculose and then to 1 mm, broadly attached; margin thin, concolorous with disk, disappearing; disk commonly depressed-convex becoming convex, brick-colored or brick-red; hypothecium pale to brownish, upper part of vertical hyphae; epihymenium pale; hymenium 45-50 μm, hyaline, 1+ blue turning red; paraphyses gelatinous, tips not thickened; asci clavate; spores oblong to slightly ellipsoid, 11-14 X 4-5 μm.

This species grows on the bark of trees, especially conifers such as Abies and Picea, less often on Betula and Alnus. It is circumpolar boreal.