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Sticta cometiella Nyl.
Family: Lobariaceae
Sticta cometiella image
Thallus: foliose, orbicular to irregularly spreading, loosely attached centrally, with free and subascendent margins, 26(-9) cm in diam. lobes: discrete to overlapping at margins, complex-folded centrally, 5-10(-15) mm wide, 10-30(-50) mm long; margins: sinuous, entire to shallowly notched or incised, slightly thickened-ridged below upper surface: dark blue-black or glaucous blue-gray when moist but when dry pale blue-gray or fawn-colored centrally and often suffused dull charcoal gray to blue-gray marginally, or becoming uniformly dark olive-brown or red-brown when dry, with minute, white, scattered (x10 lens) maculae, without phyllidia or soredia, sparsely to densely isidiate isidia: minute, granular, styliform, brown-black, glossy, very delicate and friable, in clusters at margins and along breaks or tears in upper surface, but not forming a diffractive crust medulla: white, K- photobiont: cyanobacterial lower surface: pale buff marginally, dark red-brown to brown-black centrally, tomentose from margins to center, with dense, uniform, felted to shaggy tomentum, rhizinate; rhizines: prominent, pale to dark-brown, projecting, glistening, 0.2-1 mm long cyphellae: numerous, scattered, prominent, crateriform, sunken in tomentum, rather small, round to irregular, 0.05-0.5(-1) mm in diam., with thin, slightly raised margins, with white basal membrane Apothecia: rare (only seen once), clustered near lobe margins, sessile, constricted at base, round, 0.5-1.5(-2) mm in diam. disc: dark red-brown to black, deeply to shallowly concave, somewhat shiny to dull, epruinose margins: prominent, persistent, raised above surface of disc, rounghened corrugate to minutely crenulate, with scattered, short, projecting silky, glistening, white to dark brown hairs (x10 lens); epihymenium: orange-brown, 15-20 µm thick hymenium: hyaline, 85-110 µm tall; hypothecium: yellow-brown, opaque, 40-100 µm thick asci: clavate, 8090 x 15-20 µm, 8-spored ascospores: fusiform-ellipsoid with pointed apices, 1-3-septate, 25-32(-35) x 6-8.5 µm Pycnidia: occasional to rare, developed towards margins, immersed but apparent as distinct, pale buff or brownish swellings, 0.2-0.5(-0.8) mm in diam., with a central, depressed red-brown to brown-black ostiole conidia: bacilliform, straight, 3-4 x 1 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: in oak-fir and pine-oak forest, on Quercus rugosa, and over mosses on boulders in shade, 1675-2560 m World distribution: endemic to Mexico (Hildalgo to Sonora) Sonoran distribution: Sonora, Sinaloa, and Chihuahua.