TYPE. Not indicated. “On trees; mountain woods. White Mountains. Franconia Mountains. Green Mountains in Vt. [United States, Vermont]” (Tuckerman 1841).
Description. Lichenized fungus.
[modified from Brodo et al. 2001] Thallus foliose, yellowish green, uniform, mostly appressed; lobes strap-shaped, crisped at edges, branched, 1-4 mm wide. Vegetative diaspores soredia in marginal soralia, yellowish, granular, sometimes developing from coarse pustules, rarely with tiny, almost granular lobules. Medulla white to pale orange. Lower surface pale brown to almost white, somewhat wrinkled, shiny; rhizines sparse. Ascomata lecanorine apothecia, rare, marginal or laminal; disk brown. Asci 8-spored; ascospores simple, hyaline, globose, ~5 μm diam. Conidia hyaline, variable, usually thread-shaped, 8-10 μm.
Chemistry. Medulla K+ yellow, KC+ orange to red-orange, C-, PD-; caperatic, protolichesterinic, lichesterinic, and secalonic acids.
Substrate and Habitat. On bark and wood, usually conifers, sometimes rock, typically in humid, shaded forests.
Distribution. East Asia, Europe, eastern North America; in North Carolina found in the western Piedmont and Blue Ridge ecoregions.
Notes. This species was proposed for IUCN Red List assessment in 2014 due to declining populations in Europe; however, North American populations appear stable and Asian populations need more data. IUCN is assessed as vulnerable (VU) in Europe, and Least Concern (LC) globally; assessment is considered dormant (http://iucn.ekoo.se/iucn/species_view/539329/).
Brodo, I.M., S. Duran Sharnoff & S. Sharnoff. (2001) Lichens of North America. Yale University Press, New Haven & London. 795 pp.
Tuckerman, E. (1841) A further Enumeration of some New England Lichenes. Boston Journal of Natural History. 3: 438-464 (original description as Cetraria oakesiana).