Parmeliopsis capitata R.C. Harris ex J.W. Hinds & P.L. Hinds

    Foliose thallus arranged in a rosette of 6-10 cm, formed of very dissected strip-like lobes 0.5-2 mm wide, strongly applied to the substrate and typically terminated by large globose soredia, upper surface smooth, pale yellowish green, pale yellowish gray, pale grayish, lower surface pale brown to blackish brown with simple concolorous rhizines. Apothecia rare, laminal, sessile, disc concave then flat, pale brown, gray margin. Ascospores simple, hyaline, curved, 7-12 x 3-4 µm. Pycnidia immerged, black, conidia sickle-shaped 15-18 x 1-1.5 µm. Photobiont: Trebouxia. C-, K-, KC+ yellow, P-. A subarctic species native to boreal forests, endemic to North America.

N.B. A species very closely related to Parmeliopsis ambigua, differing only in its terminal globose soredia.

N.B. A species very often associated with Cetraria pinastri.