Family: Physciaceae
[ Berengeria exigua (Ach.) Trevis. , more, Courtoisia exigua (Ach.) March., Lecanora exigua (Ach.) Röhl., Lecanora exigua f. exigua (Ach.) Röhl., Lecanora exigua f. subrufecens Nyl., Lichen exiguus Ach., Parmelia exigua (Ach.) Ach., Parmelia exigua var. exigua (Ach.) Ach., Parmelia exigua var. pinicola Ach., Patellaria exigua (Ach.) DC., Psora exigua (Ach.) Nägeli, Psora exigua var. maculiformis Hepp] |
Global occurrence: Africa (incl Madagascar) | Eurasia – Europe | Americas – North America (incl Mexico) | Arctic. Substrate: wood – dead, living | bark, cork, plant surface – trunks, branches, twigs. Life habit: lichenized (mutualistic with algal photobionts). Thallus: crustose (crustaceous) – episubstratal – unspecified; continuous, diffuse, effuse | cracked, fissured, fractured, rimose; [th] upper surface: grey(ish) | white(ish) | white(ish) brown (beige); [th upper surface]: epruinose; [th marginal and upper surface] specific structures: absent; [th] morphol substructures (eg areoles, lobes, branches) upper surface: smooth, plane | granulose, granular. Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (low) 0.3 (high) 0.6 (max) 0.7; ascoma: immersed, innate | subsessile, subimmersed, adnate, semi-immersed, emergent | sessile, superficial; [ascm, if apoth] disc, mazaedium: plane, flat, flattened, expanded; [ascm, if apoth] disc, mazaedium: black(ish); [ascm, if apoth] disc, mazaedium: epruinose; [ascm, if apoth] margin surface; [if perith] periostiolar area, ostiole, involucrellum: grey(ish) | white(ish) | white(ish) brown (beige); [ascm, if apoth] margin excipular photobionts: absent | present; [ascm, if apoth] subhymenial layers, hypothecium; [if perith] basal excipulum: hyaline, colourless; [ascm] paraphyses/-oids: present; [ascm] epihymenium, epithecium: brown(ish) (if pale: fawn, tan; if mid: cinnamon) | grey(ish) brown | yellow(ish) brown | red(dish) brown (pale: orange brown). 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: ellipsoidal; [asp] length [µm]: (low) 15.0 (high) 21.0 (max) 23.0; [asp] width [µm]: (low) 7.0 (high) 9.0 (max) 10.0; [asp] septa: present; [asp] septa: transversely septate; [asp] transversal septa: (median) 1.0; [asp] pigmentation: pale brown | medium brown, brownish | dark brown; [asp] perispore, epispore: ornamented, rough, warted, striate, cracked. Secondary metabolites: present, atranorin. Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid. Secondary photobionts (eg in cephalodia): absent. |