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Absconditella lignicola Vezda & Pisut
Family: Stictidaceae
Absconditella lignicola image
Robin Schoeninger  
Thallus: very thin, granulose-leprose, swelling when wet surface: dark green photobiont: apparently chlorococcoid (thallus overgrowing various algal colonies; hyphae: appearing to be associated symbiotically with small, spherical algal cells 5-6 µm diam.) Apothecia: semiimmersed to adnate, broadly sessile but may be immersed in the various algal colonies and the uppermost layes of the substrate tissues, whitish pale waxy yellow when dry, hyaline when moist; round, 0.1-0.2(-0.27) mm in diam., c. 0.05 mm thick disc: concave or later plane, margin: scarcely raised, moderately thick, entire exciple: hyaline in longitudinal section, laterally 40-50 µm wide, basally c. 20 µm wide; hyphae: conglutinated, parallel hymenium: hyaline, 60-65(-70) µm high; paraphyses: very dense, slender, simple or occasionally forked at the tips, 0.5-0.8 µm wide, in rich gelatin, in upper part rounded, thin walled; tips: irregularly broadened; ascogenous layer: little developed, the structure indistinct asci: long cylindrical, 8-10 µm wide when mature, the upper part rounded, thin walled at the apex but +cap-form thickened, when mature the center of the cap penetrated by a long, narrow tube extending upwards from the endoascus, 8-spored ascospores: 3-septate, broadly ellipsoid, 10-15 x 4.5-6.5 µm, with very thin walls and septa, straight, sometimes slightly constricted at the septa Pycnidia: not observed Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on moist wood of Picea, in spruce-fir forest World distribution: Europe and North America Sonoran distribution: eastern Arizona in the White Mountains. Notes: In its whitish to yellowish wax-colored, relatively broad apothecia [resembling those of Dimerella pineti (Ach.) Vězda but smaller, less urceolate and more en-sunken], Absconditella lignicola is similar externally to A. annexa (Arnold) Vězda and A. pauxilla Vězda & Vivant, but is well distinguished from those species through the different spore structure. A. lignicola seems to be a species of the temperate to boreal ecozones reaching the area of the flora only in the northern part and in high altitudes.