[Crocynia rigidula B. de Lesd.]
Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: totally leprose, irregular, indeterminate, not becoming loose from the substrate, up to several cm in diam. upper surface: pale bluish gray to whitish gray, often fading to white in the herbarium, sorediate soredia: mainly fine but also coarse, up to 100 µm wide, with up to 75(-120) µm long projecting hyphae, fluffy medulla: not evident lower surface: not evident Spot tests: K+ yellow or K-, C-, KC-, P- orange Secondary metabolites: atranorin and nephrosteranic acid. Substrate and ecology: on mosses and bark (Pseudotsuga menziesii) World distribution: Africa, Asia, Europe and North America Sonoran distribution: Arizona at 26503350 m.