LICHALP

Rhizocarpon petraeum (Wulfen) A. Massal.

Syn.: Lecidea petraea (Wulfen) Ach., Lichen petraeus Wulfen, Patellaria petraea (Wulfen) DC., Rhizocarpon concentricum auct. non (Davies) Beltr., Rhizocarpon excentricum (Ach.) Arnold, Rhizocarpon perlutum auct. non (Nyl.) Zahlbr., Rhizocarpon richardii auct. non (Nyl.) Zahlbr., Rhizocarpon subconcentricum (Körb.) Körb., Siegertia petraea (Wulfen) V. Wirth; incl. Rhizocarpon variegatum J. Steiner

Lichenised.

Substrate: siliceous rocks, intermediate rocks (such as calciferous schists)

Altitudinal range: from the mesomediterranean belt (potential vegetation: evergreen broad-leaved forests dominated by Quercus ilex) 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 holarctic pioneer species of base-rich siliceous rocks, often found on old roofing tiles and on slightly calciferous sandstone, with a wide altitudinal range; widespread throughout the Alps.