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Lepraria nivalis J. R. Laundon
Family: Stereocaulaceae
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Thallus: crustose, rosette-forming to irregular, determinate, sometimes distinctly wrinkled and folded and ┬▒loose from the substrate, with distinct lobes with a thickened and raised margin upper surface: white, yellowish white, or sometimes pale bluish gray, sorediate soredia: not compacted, in some specimens mostly fine except at the thallus margin where they usually are coarse, in other specimens a mixture or fine to coarse ones throughout; coarse soredia: often with long projecting hyphae medulla: distinct in thick specimens, lower surface: often with a distinct tomentum of brown hyphae Spot tests: K+ yellow, C-, KC-, P+ orange Secondary metabolites: atranorin, protocetraric and roccellic acids. Substrate and ecology: on rocks, including granite, sandstone, rhyolite, basalt, and often on cliff-faces World distribution: Asia, Europe and North America Sonoran distribution: Arizona at 1400-2260 m.