Order: Lecanorales Family: Rhizocarpaceae
Species: Rhizocarpon oederi
Photos: On upland rock. Ballingeary area, Co. Cork, SW Ireland.
Identification needs confirming
Crustose, rimose or areolate, matt ochre to deep orange-brown thallus with +/- angular areoles. Indistict prothallus. Apothecia are less than 0.6mm diam with uneven, gyrose brown-black discs. Epithecium olive-dark green. Spores colourless, mainly 3-septate, 12-20 x 3-8 Ám.
Occurs on exposed, iron-rich upland rocks, often associated with mines or quarries. Most records are from NW Ireland.
Chemical reactions negative.
Similar: Tremolechia atrata and Lecidea lithophila
Rhizocarpon oederi. Ballingeary area, July 2009