ASCOMYCOTA | LECANOROMYCETES > LECANORALES > Parmeliaceae

Common name:            Shiny Camouflage Lichen

Synonyms:                    Melanelixia fuliginosa ssp.glabratula, Melanelia glabratula

Habitat:                         Woodland, wayside trees

Substrata:                     Bark

Growth form:                Corticolous (saxicolous)

Thallus:                  Foliose

Apothecia:                    Lecanorine, occasional

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

Thallus rosette-forming  or irregular, typically from 2-8cm across, closely appressed centrally, but usually free at the margins; lobes flat, although often turned up at the margins, contiguous or overlapping, 2-5mm wide, apices wavy to crenulate.  

Upper surface glossy, especially towards the lobe ends; green when moist to greenish-brown or olive brown when dry, sometimes with a reddish tinge. Underside black with a brown marginal zone; rhizines pale brown, unbranched.

Isidia cylindrical, arising singularly, smooth, becoming branched-corralloid, neater and more regular in shape than Melanelixia subaurifera, not becoming sorediate; usually, although not always, numerous, but can often obscure the centre of the thallus; leaves a white area if eroded.

Apothecia infrequent but, where present, very shortly stalked, to 5mm dia., disc red-brown and shiny, thalline margin often becoming isidiate.

Melanelixia glabratula is a common and widespread species, occurring on bark of many species of broadleaved trees, rarely on conifers; also possible on both siliceous stone and basic rock.

Confusion can arise when specimens are not fully isidiate (as with those featured below), when species such as Melanohalea elegantula might be considered, but that species is darker brown, always heavily isidiate when it reaches a certain size, more appressed and less shiny. The general appearance and shape of the lobes, coupled with the green colour and shining surface, are all good visual field characters for distinguishing Melanelixia glabratula.

For the record, I was not sure about the following examples, so I was pleased when the identity was confirmed by an experienced lichenologist on the FB group, which I've referred to on the accompanying write-up about lichens being a challenge.