Thallus: adnate to rather loosely adnate, appressed to pulvinate, foliose, up to 11 (-14) cm diam., lobate lobes: short and rounded to somewhat elongate and angular, ± contiguous to imbricate or somewhat entangled, (0.5-) 1-3 (-5) mm broad, ± flat upper surface: pale yellow (rarely) to yellowish or reddish brown, occasionally dark brown, usually paler at the periphery, smooth to weakly wrinkled or pitted at the periphery, inward becoming rugose and/or fissured; dull throughout or slightly shiny on the lobe ends, occasionally pruinose, especially on the lobe ends isidia: laminal, sparse to dense, ± spherical and distinctly pustular, 0.1-0.5 mm in diam., sometimes proliferating to form rather deep cushions, easily abraded and then mistaken for soredia lower surface: dark brown to black, sometimes paler on the lobe ends; smooth to somewhat rugulose, ± dull; moderately rhizinate, the rhizines concolorous with the lower surface Apothecia: uncommon, up to 6 mm diam., sessile to short stipitate, concave or flattening, the margin entire to slightly crenate, when older often bearing pustular isidia asci: clavate, 8-spored ascospores: ellipsoid, 8-10 x 4-5 µm Pycnidia: rare, immersed conidia: bifusiform, 5-6 x 1 µm Spot tests: cortex K-, C-, KC-, P-, HNO3+ pale to dark blue-green; medulla K- or dingy, C- or C+ slow yellow or (rarely) C+ rose, KC+ red turning dingy orange-red, P- Secondary metabolites: glomelliferic and glomellic acids (both major), perlatolic acid (minor), rarely with gyrophoric acid (minor). Substrate: rock, very rare on wood or bark World distribution: western North America, Europe, North Africa, Asia Sonoran distribution: infrequent, in southern California. Notes: Neofuscelia loxodes is morphologically most like N. subhosseana, which however can be easily distinguished by the K+ yellow turning red medullary spot test (hypostictic acid, et al.). A morphologically similar species which also has spot tests similar to those of N. loxodes, is N. verruculifera, which differs by the somewhat darker, smaller thalli, with narrower and thinner, mostly emaculate lobes, and production of divaricatic acid as the major constituent. That species is usually KC- or very faint in the medulla, unless accessory gyrophoric acid is present. Occasional specimens of these two species will require TLC analysis to be certain of their identity, especially poorly developed ones.