ASCOMYCOTA | LECANOROMYCETES > LECANORALES > Parmeliaceae

Common name:            Abraded Brown-shield Lichen

Synonyms:                    Melanelia subaurifera, Parmelia subaurifera

Habitat:                         Woodland, wayside trees

Substrata:                     Mainly smooth bark

Growth form:                Corticolous (lignicolous, saxicolous)

Thallus:                  Foliose

Apothecia:                    Lecanorine, but rarely

BLS identity rating:        Graded 1/5 (identification should be straightforward)

Thallus typically rosette-forming up to 5cm across, occasionally larger; closely appressed centrally, but usually free and upturned at the margins; lobes radiating, mainly flat, often overlapping, 3-5mm wide, variably shaped with scalloped, irregularly incised, margins.

Upper surface brown to green-brown, occasionally with a bronze or copper-coloured tinge; mainly with a dull, non-reflective appearance, although some specimens in exposed locations may appear glossy, particularly towards the lobe margins. Underside dark brown to black with concolourous rhizines.

The lobes are faintly to extensively pitted with small irregular swellings that arise and then break down with soredia developing from which isidia are derived, often arising in clusters, which are easily abraded leaving pale, sometimes yellow tinged, patches.

Apothecia are rare but, where present, to around 2mm dia., thalline margin sorediate.

Melanelixia subaurifera is a common, almost ubiquitous, widespread species primarily occurring on smooth-barked nutrient- enriched deciduous trees, as well as occasionally on fences and, more rarely, on rocks. Corticolous forms may be found on smaller trunks, branches and twigs, but less frequently on the trunks of larger trees.

It could be confused with the closely related Melanelixia glabratula, which has a not dissimilar general appearance other than the lobes have a shinier upper surface lacking soredia; also, with branched, true isidia, that are neater and more regular in shape, and which more or less cover the centre of the thallus.