Irish lichens

Rhizocarpon oederi

Order: Lecanorales       Family: Rhizocarpaceae

Species: Rhizocarpon oederi

Growth type crustose.
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 is olive or dark green. The spores are colourless and 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

Rhizocarpon oederi

Rhizocarpon oederi
Rhizocarpon oederi. Ballingeary area, July 2009

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