ASCOMYCOTA | LECANOROMYCETES > PERTUSARIALES > Ochrolechiaceae

Genus, formerly Pertusaria, meaning 'bored-through' - from the shape of the apothecia of the type species, but now Varicellaria, which was separated from the Pertusariaceae some years ago.

Common name:            -

Synonym:                    Pertusaria lactea

Habitat:                         Montane (for this entry)

Substrata:                     Rock

Growth form:                Saxicolous

Thallus:                  Crustose

Apothecia:                    Lecanorine, but very scarce

BLS identity rating:        Graded 2/5 (possible, although spot testing recommended to be sure)

Thallus rather thick, wide-spreading, to around 15cm dia., surface smooth to slightly roughened, matt, cracked and areolate; creamy white to pale greyish-white, with paler prothallus; covered with more or less globose, sometimes irregularly rounded or angular, whitish soralia, up to 1.5mm dia., often surrounded by a fragile thalline collar; very rarely fertile; apothecia if present in warts that resemble the soralia, disc initially white-pruinose, then flesh-coloured.

Found on dry, mostly sunny, siliceous or occasionally calcareous rocks and boulders throughout upland and some coastal areas of west and northern Britain. In Austria, where these photos were taken, the species is described as "optimum on steeply inclined, lime-free, rather shaded surfaces of siliceous rocks in humid areas, rarely corticolous; widespread throughout the Alps".