ASCOMYCOTA | ARTHONIOMYCETES > ARTHONIALES > Lecanographaceae

Formally genus Opegrapha, meaning 'hidden writing' from the small lirellae; now Alyxoria with only limited morphological differences other than Alyxoria species tend to have more open apothecia

Common Name:           -

Synonym:                     Opegrapha ochrocheila

Habitat:                         Woodland, wayside trees, shrubs

Substrata:                      Smooth bark

Growth form:                Corticolous

Thallus:                 Crustose

Apothecia:                    Lirellate

BLS identity rating:        Graded 3/5 (microscopic examination required to verify)

Thallus immersed, often inconspicuous, or very thin whitish-grey, occasionally with a brownish or olive-green tinge, invariably with some of the bark colour showing through; apothecia in the form of small, scattered or contiguous, very slightly raised lirellae, typically 0.5-1.5mm (2.5mm max.) long x 0.25-0.4mm wide, sessile, variable, sometimes irregularly gnarled, simple or wavy, seldom branched, and only rarely star-shaped; black, typically with a brown-orange pruina around and along the slit, which is usually rather open.  

Alyxoria ochrocheila is a widespread, albeit local species, primarily found on old dry, shaded bark, especially Oak (Quercus) in well-wooded locations; also frequent on Ash (Fraxinus), Beech (Fagus) and Holly (Ilex); more rarely on sheltered siliceous rocks.

Forms with non-pruinose apothecia may be mistaken for Alyxoria culmigena, which has broader ascopores with a usually more distinctive swollen second cell, shorter conidia and other features that require microscopic examination. However, visually, Alyxoria culmigena lirellae usually have some greyish pigments on the margins (excipulum), not seen here, and tend to have more pointed ends.

The photo of the small example featured here was viewed by an experienced lichenologist who was pretty sure it was Alyxoria ochrocheila for the reasons stated above. However, without microscopic examination, it has to be regarded as a 'likely' rather than confirmed identification.