LICHALP

Caloplaca atroalba (Tuck.) Zahlbr.

Syn.: Placodium atroalbum Tuck.

Lichenised.

Substrate: calciferous rocks

Altitudinal range: from the subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron) to the alpine belt (potential vegetation: treeless Alpine grasslands and tundras, to the lower limit of perennial snow and the equilibrium line of glaciers)

Note: a species with a rimose to areolate, yellowish-brownish thallus, apothecia with zeorine proper margin, a white thalline margin, black disc and amphithecium; on limestone and calcareous sandstone; based on a type from Western North America, the identity of European records is in need of re-evaluation.