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Hypotrachyna rockii (Zahlbr.) Hale
Family: Parmeliaceae
[Parmelia rockii Zahlbr.]
Hypotrachyna rockii image
Laurens Sparrius  
Thallus: foliose, 3-12 cm in diam., tightly adnate to adnate, subdichotomously to irregularly lobate lobes: sublinear to somewhat subirregular, short to elongate, initially separate, becoming slightly imbricate, 1.5-5 mm wide; margin: entire, rarely lobulate; apices: subtruncate to subrotund, plane to subconvex upper surface: whitish gray, smooth to slightly rugulose and occasionally becoming cracked centrally, shiny, often white maculate, becoming pruinose towards apices soredia: initially farinose but soon granular, in laminal, crateriform, slightly excavated pustulae that sometimes become confluent; isidia and dactyls absent medulla: white with continuous algal layer lower surface: black with brownish apices, somewhat shiny; rhizines: sparse, black, dichotomous Apothecia: rare, sparse, laminal, sessile to substipitate, 2-8 mm in diam.; disc: brown; margin: crenulate, sometimes sorediate asci: clavate, 8-spored ascospores: ellipsoid, 11-14 x 5-7 ┬Ám Pycnidia: not seen Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow, UV-; medulla K-, C+ red, KC+ red, P- Secondary metabolites: upper cortex with atranorin and chloroatranorin; medulla with evernic acid (major) and lecanoric acids (minor to major). Substrate and ecology: on bark (especially pines) in montane forests World distribution: neotropics and East Africa in montane and upper montane forests Sonoran distribution: Sinaloa in the Sierra Madre Occidental.