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Hypotrachyna laevigata (Sm.) Hale
Family: Parmeliaceae
[Imbricaria laevigata (Sm.) Arnold,  more]
Hypotrachyna laevigata image
Stephen Sharnoff  
Thallus: foliose, 2-10 cm in diam., adnate to loosely adnate, subdichotomously lobate lobes: sublinear to subirregular, elongate, subconcave to plane to subconvex, initially separate, becoming imbricate, 1-6 mm wide; margin: entire to rarely incised; apices: subtruncate to subrotund upper surface: whitish to greenish gray, smooth to rugulose, dull to shiny, usually strongly white maculate soredia: farinose to granular, white but darkening with age, in laminal to subapical, capitate, slightly excavated soralia, not confluent; isidia, pustulae and dactyls all absent medulla: white with algal layer lower surface: black, sometimes with a thin, brown rim, tips brownish black; rhizines: dense, black, dichotomous Apothecia: rarely, sparse, laminal, sessile; disc: brown; margin: crenulate, epruinose and without soredia ascospores: mature spores not found Pycnidia: marginal, immersed conidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K-, C+ yellow-orange, KC+ yellow-orange, P- Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with 4-O-demethylbarbatic and barbatic acids (both major), obtusatic and norobtusatic acids (trace). Substrate and ecology: on hardwood bark and occasionally conifers in lower to upper montane forests World distribution: tropics and extending into some temperate regions in Europe, North and South America and Australasia Sonoran distribution: mountains of SE Arizona southwards through the Sierra Madre Occidental to Durango.