LICHALP

Acarospora rosulata (Th. Fr.) H. Magn.

Syn.: Acarospora discreta (Ach.) Th. Fr. f. rosulata Th. Fr.

Lichenised.

Substrate: siliceous 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: characterised by the rosulate thalli with indistinctly lobate peripheral squamules with a whitish lower surface, this species, described from Norway where it is rare, is known from Western North America, Asia (Mongolia) and the Alps. It grows on sun-exposed siliceous rocks, with optimum in dry, subcontinental areas; being easily overlooked, the species might be more widespread in the Alps.