[Fuscopannaria hookerioides P. M. Joerg.]
Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: squamulose, forming small cushions, up to 2 cm broad, on a poorly developed hypothallus squamules: up to 2 mm diam. upper surface: dark greenish brown, uneven upper cortex: paraplectenchymatous with irregularly thickened cell walls, 20-30 µm thick Apothecia: black, with a strongly developed thalline margin; disc: flat and distinct; exciple: often poorly developed, subparaplectenchymatous, up to 50 µm thick; hymenium: I+ blue-green and rapidly turning red-brown, up to 100 µm high asci: clavate, with apical amyloid sheets, 8-spored ascospores: simple, colorless, fairly thick-walled, often with one or two oil droplets, ellipsoid, 10-12 x 6-7 µm Pycnidia: not observed Spot tests: all reactions negative Secondary metabolites: none detected. Substrate and ecology: mostly on wet, acidic rocks at high altitudes World distribution: arctic-alpine, mainly known from the Rocky Mountains, Greenland , Labrador and rarely in Fennoscandia Sonoran distribution: rare, only collected once in the high peaks of eastern Arizona (Escudilla Mt.) above 3000 m. Notes: Previously this material was placed with the arctic-alpine Pannaria hookeri on the basis of the strongly margined, black apothecia found in both species. However, the thallus of F. hookerioides is more pulvinate and squamulose, and it lacks the marginal lobes and whitish striae found in P. hookeri. Also P. hookeri has an amyloid hymenium and asci that lack amyloid apical structures. Fuscopannaria hookerioides is the only truly arctic-alpine species of the F. leucophaea-complex and is easily recognized by its characteristic apothecia and the small spores. Extreme specimens with narrow lobes approach those of F. californica, which has much larger spores.