ASCOMYCOTA | LECANOROMYCETES > PERTUSARIALES > Pertusariaceae

Genus Pertusaria, meaning 'bored-though' - from the shape of the apothecia of the type species

Common name:            Covered Lichen

Synonym:                    -

Habitat:                         Woodland and wayside trees

Substrata:                     Smooth bark

Growth form:                Corticolous

Thallus:                  Crustose

Apothecia:                    Lecanorine

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

Appearance variable; thallus superficial, either forming small patches or more widely spreading, thin to moderately thick, with a somewhat waxy surface, which is smooth in young thalli, but becoming rough, often tuberculate, wrinkled or cracked, the margin usually entire; upper surface can be yellowish-grey in sheltered sunny sites, but more typically greyish to dull greyish-green, becoming brighter and greener when moist; usually fertile with apothecia in concolourous wart-like protuberances, to 2mm dia., either in small groups or completely covering the centre of the thallus, semi-globose and often distorted, normally one in each wart, whereas the somewhat similar Pertusaria pertusa has several; discs rounded or irregular, often pinkish when young, turning dark, brown or dark grey to black, sometimes thinly pruinose, also widening and more open than in Pertusaria pertusa making the discs more visible, surrounded by an uneven, somewhat elevated, thalline margin; in shaded sites, the apothecia can develop widely exposed, pale, Lecanora-like, discs. In more exposed sites, the discs tend to be darker.

Relatively common and widespread, especially in the south and west. Occurring on the trunks of woodland, parkland or wayside broadleaved trees, most frequent on those that are smooth-barked and in shade; also, but rarely, on sheltered rocks in woodland.