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Catapyrenium dactylinum Breuss
Family: Verrucariaceae
Catapyrenium dactylinum image
Othmar Breuss  
Thallus: squamulose, irregularly rosulate squamules: densely aggregated to form orbicular, flattened cushions up to 30 mm across; individual squamules: 1.5 - 2.5 mm wide, 0.25-0.35 mm thick, slightly convex and undulate or flattened, the outer squamules: somewhat enlarged and weakly concave; central squamules: irregularly divided into erect, nodular or slightly elongated, inflated lobes or lobules up to 0.35 mm wide upper surface: brownish gray, dull, densely covered by granular pruina (lobules less densely pruinose, their extreme tips often epruinose and brown) medulla: composed of intricated filamentous hyphae without spherical cells; hyphae: 2.5-3 micro meter in diam.; medulla of lobules: more loosely organized to almost arachnoid; algal layer: 30-50 micro meter thick, algal cells 5-8 micro meter in diam. lower cortex: thin, composed of 1-3 layers of brownish, roundish-angular cells (8-12 micro meter in diam.); rhizohyphae: lacking lower surface: brown centrally, pale marginally, dull, naked, attached by their elongated basal ends Perithecia: subglobose, up to 0.25 mm broad; exciple: colorless or yellowish asci: narrowly clavate, 50-55 x 12-16 micro meter, 8-spored ascospores: narrowly ellipsoid, 14-17 x 5-6 micro meter Pycnidia: immersed in the apices of erect lobules conidia: shortly cylindrical, 3.5-4 x 1 micro meter Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on mosses over acidic rock World and Sonoran distribution: known only from the type locality in Chihuahua. Notes: The formation of nodular or finger-like lobules with a loosely filamentous medulla is distinctive. The species is the only member of the genus known to have pycnidia.