LICHALP

Rhizocarpon grande (Flörke ex Flot.) Arnold

Syn.: Lecidea petraea (Wulfen) Ach. f. grande Flörke ex Flot., Rhizocarpon endamyleum Th. Fr.

Lichenised.

Substrate: siliceous rocks, bark

Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)

Note: a silicicolous species resembling Rh. eupetraeum in the faintly amyloid medulla, the 8-spored asci, and the eumuriform spores soon becoming green-brown, but medulla K+ yellow or K-, with a different secondary chemistry, and ascospores larger (to c. 50 µm long); widespread in Europe, including the Alps, but the known distribution is lacunose, since the species was not always distinguished from Rh. eupetraeum.