Irish lichens
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Order: Lecanorales Family: Rhizocarpaceae
Species: Rhizocarpon lavatum Photos: On stones in wall. Gougane Barra, Cork, SW Ireland. Identified by John Douglass Grey to pale ochre-brown thallus, greener when wet or shaded, smooth or cracked. Prothallus weak or absent. Apothecia +/- flat, discs black, not pruinose, thick persistent dark-brown margins. Asci 8-spored, spores muriform, colourless, 30-40 x 14-18 µm. Occurs on damp siliceous rocks near upland streams and lake edges. Chemical reactions negative. Similar: Rhizocarpon reductum. Usually K+ yellow, P+ orange. |
Rhizocarpon lavatum. August 2009