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Usnea glabrescens (Nyl. ex Vainio) Vainio
Family: Parmeliaceae
[Usnea barbata var. glabrescens Nyl. ex Vain.,  more]
Usnea glabrescens image
Andrew Khitsun  

Global occurrence: Eurasia – Europe | Americas – North America (incl Mexico) | Arctic.  Substrate: bark, cork, plant surface – trunks, branches, twigs.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: fruticose (fruticous), shrub-like, beard-like; thallus: continuous, diffuse, effuse; [th] upper surface: green(ish) | yellow(ish) (if dull: buff) | yellow(ish) grey | grey(ish) green; [th upper surface]: epruinose; [th marginal and upper surface] specific structures: present; [th margin] cilia, cilioid structures: absent; [th upper surface] isidia, isidioid structures: absent; [th upper surface] soredia, soralia, soralioid structures: present; [th] morphol substructures (eg areoles, lobes, branches) width [mm]: (median) 1.5; [th] morphol substructures (eg areoles, squamules): distantly discontiguous; [th] morphol substructures (eg areoles, lobes, branches) upper surface: smooth, plane | verrucose, warted.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (min) 5.0; [ascm, if apoth] disc, mazaedium: plane, flat, flattened, expanded; [ascm, if apoth] disc, mazaedium: pruinose; [ascm, if apoth] disc, mazaedium pruina: scarce, sparse, fine; [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] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless.  Secondary metabolites: present; secondary metabolites: norstictic acid | psoromic acid | salazinic acid | stictic acid | usnic acid.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.