Lichens of Belgium, Luxembourg and northern France
Rhizocarpon petraeum (Wulfen) A. Massal. |
Syn.: R. concentricum auct., non (Davies) Beltr., R. excentricum (Ach.) Arnold, R. perlutum (Nyl.) Zahlbr.
On rocks containing some quantities of calcium, incl. siliceous and sandstone rocks and hard "clay", in natural or artificial conditions.
Belgium: Mosan: R.
Luxembourg: Ard.: RRR, Lorr.: RRR (<1850).
France: Mosan: RRR.
Lit.: DG: 25, La69: 103.