Melanelixia subaurifera

Appearance

Thallus: adnate to loosely adnate appressed throughout or occasionally slightly reflexed at the periphery, foliose, up to 8 (-10) cm diam., lobate lobes: short and rounded to somewhat elongate, discrete to more often contiguous or subimbricate, 1-4 (-6) mm broad, ± flat upper surface: olive-green or olive-brown to rather dark reddish brown, smooth to weakly pitted or rugulose near the periphery, inward usually somewhat more strongly rugose; dull throughout or occasionally shiny, especially near the periphery; sometimes with small and very obscure, concolorous pseudocyphellae on the lobes; sorediate or isidiate or (usually) both isidia: arising within but also between the soralia, cylindrical, not or infrequently branched, to 0.2 (-0.4) mm long and 0.02-0.06 mm diam. soredia: granular, frequently becoming brownish and isidioid or isidiate; in laminal soralia that often arise from the obscure pseudocyphellae and are punctiform and discrete, or become ± confluent in central parts lower surface: pale brown to dark brown or black, often paler at the periphery; ± smooth to rugose, dull to rather shiny; moderately rhizinate, the rhizines concolorous with the lower surface Apothecia: rare, up to 2.5 mm diam., sessile, ± flat, the margin entire when young, soon sorediate and isidiate asci: clavate, 8-spored ascospores: ellipsoid, 10-13 x 5.5-7 µm Pycnidia: rare, immersed conidia: weakly fusiform to weakly bifusiform, 5.5-7 x 1µm Spot tests: cortex K-, C-, KC-, P-, HNO3-; medulla K-, C+ rose-red or red, KC+ red, P- Secondary metabolite: lecanoric acid.

Naming

Melanelixia subaurifera (Nyl.) O. Blanco, A. Crespo, Divakar, Essl., D. Hawksw. & Lumbsch
Imbricaria subaurifera (Nyl.) Arnold
Melanelia subaurifera (Nyl.) Essl.
Parmelia subaurifera Nyl.
Parmelia subaurifera f. fuliginoides B. de Lesd.
Parmelia subaurifera f. isidioidea H. Olivier
Parmelia subaurifera f. laciniata Maas Geest.
Parmelia subaurifera f. minuta (Erichsen) Rass.
Parmelia subaurifera f. subaurifera Nyl.
Parmelia subaurifera var. fuliginoides (B. de Lesd.) Frey
Parmelia subaurifera var. minuta Erichsen
Parmelia subaurifera var. subaurifera Nyl

Distribution

Much of temperate and boreal North America and Europe, North and Central Africa, Asia

Habitat

On trees, especially the smaller branches and twigs, such as willow or black walnut, or wood, rarely on rocks.