ASCOMYCOTA | LECANOROMYCETES > LECANORALES > Parmeliaceae

Genus Hypotrachyna, meaning 'rough below' - referring to the appearance of the lower surface due to the numerous rhizines

Common name:            Powdered Loop Lichen

Synonym:                    Parmelia revoluta

Habitat:                         Ubiquitous

Substrata:                     Bark, primarily, occasionally on rock and stone

Growth form:                Corticolous and saxicolous

Thallus:                  Foliose

Apothecia:                    Lecanorine, but rare

BLS identity rating:        Graded 2/5 (visual identification possible with care)

Thallus rather compact, usually no more than 6cm across, although sometimes adjoining and forming more extensive patches; lobes relatively broad, up to 5mm, appressed, separate, but overlapping towards the centre, rounded and slightly rolled down at the margin; upper surface pale smooth, glossy, grey-blue to grey-green, with a light yellow-brown edge so that the lobes look slightly burnt around the margin; lower surface dark brown towards the lobes, black at the centre, with short, simple rhizines.

Apothecia rare, but if present, discs to 6mm dia., thalline margin sorediate.

The species is very similar to Hypotrachyna afrorevoluta, but has a less 'three dimensional' appearance with soredia forming on less erect lobes.

Widespread and fairly common on trees, mainly on the trunk and upper branches, more rarely on weakly acidic rocks, walls and memorials; found in both coastal and inland locations.

Unfortunately, I only have photos of two poor examples at present. The first, mixed in with Physcia aipolia and Physcia tenella was on a small branch that had been broken off by the wind. The second is likely, but too immature to rule out Hypotrachyna afrorevoluta.