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Lecanora valesiaca (Mull. Arg.) Stizenb.
Family: Lecanoraceae
Lecanora valesiaca image
Thallus: crustose to +placodioid, rimose-areolate to areolate, rosulate, usually forming distinct rosettes 1-2(-4) cm in diam., 0.1-0.5(-1) mm thick, plane to slightly thickened in center; sometimes coalescing, sometimes scattered and irregular; usually closely and completely adherent to the substrate; prothallus: absent areoles: contiguous, 0.5-0.7 mm across, plane lobes: plane to convex (flattening towards periphery), 1-2(-5 mm) long, usually clearly radiating, moderately crenate-incised, the ultimate segments 0.3-0.7 mm wide; edges: towards tips, often raised or thickened, forming rims upper surface: pale greenish yellow but densely pruinose throughout, appearing yellowish white, extreme tips of lobes sometimes blackening, esorediate upper cortex: without dead algal cells, rather distinctly delimited, 20-30 µm thick, with strongly swollen hyphal tips, without distinct conical hyphal bundles, inspersed almost throughout with grayish crystals (insoluble in K) which also cover the surface; epinecral layer: not evident medulla: thin, moderately dense, thickly inspersed with grayish granules (insoluble in K), with thick-walled, +randomly oriented hyphae 3-5 µm in diam. and with thread-like lumina; algal layer: +uniformly c. 50 µm thick, continuous to interrupted lower cortex: absent or poorly developed lower surface: pale Apothecia: common, semi-immersed then becoming sessile and +constricted, 0.5-1.5(-2) mm in diam. disc: usually moderate yellow to pale orange or brown, or (in var. siberica) often at least spottily green and N+ when young and near the margin, becoming olivaceous or yellowish green to greenish black, plane or occasionally convex, sometimes roughened and cracked, +dull, epruinose margin: entire to flexuous or crenate, persistent, level with disc, either without a parathecial ring or with an indistinct, narrow parathecial ring paler than the disc and 0.1-0.15 mm wide cortex: similar to that of thallus amphithecium: present, with an algal layer developed marginally in upper part and extending below the hypothecium, with coarse crystals (insoluble in K) in the medulla, similarly corticate to the thallus parathecium: inner part hyaline to pale yellow and translucent, pol-, outer part opaque and pale gray, pol+, composed of +parallel, conglutinated, +randomly oriented hyphae c. 5 µm in diam. epihymenium: inspersed with fine yellow-brown granules (soluble in K), 10-30 µm thick hymenium: hyaline, 55-70 µm tall; paraphyses: tips: hyaline and scarcely thickened, or (var. siberica) green-black and strongly thickened, up to 2.5 µm thick; subhymenium: pale gray, 30-60 µm thick; hypothecium: bowl-shaped to conical, 30-130 µm thick centrally asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid to broadly ellipsoid or ovoid-ellipsoid, 9-11 x 5-6 µm Pycnidia: immersed, sometimes common but very small and often inconspicuous, ostiole: pale yellow to green; conidiophores: type III of Vobis (1980) conidia: filiform, mostly curved, 15-20 µm long Spot tests: thallus and apothecia K-, C-, KC-, P-; cortex KC+ pale yellow; discs when at least partly green N+ red-violet Secondary metabolites: cortex with usnic acid; medulla with roccellic acid. sibirica: Poelt, Mitt. Bot. Staatssamml. München 19
Lecanora valesiaca image
Lecanora valesiaca image
Andrew Khitsun  
Lecanora valesiaca image
Lecanora valesiaca image
Lecanora valesiaca image
Lecanora valesiaca image
Andrew Khitsun  
Lecanora valesiaca image
Lecanora valesiaca image
Lecanora valesiaca image
Lecanora valesiaca image
Andrew Khitsun