• Rhizocarpon richardii (Nyl.) Zahlbr.
Rhizocarpon richardii
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(Map updated: 11 August 2009)

This crustose, coastal lichen resembles crazy paving. It has a brown, C+ red, cracked thallus with a grey-violet cast, scattered with black discs. The species has a black prothallus (a kind of base which it sits on) which shows as a black margin around the edge of the thallus and as black veining through the cracks. It is most frequent on cliffs of siliceous rock in maritime areas where it occurs above the orange lichen zone. It is widely occurring along all coastal areas of Ireland.

Key characteristics

  • The colour, habitat and C + red reaction of the cortex should help to separate it
  • The species never strays far from the sea.

Original text submitted by Simon Davey

 Simms, M. J., (2016). Rhizocarpon richardii (Nyl.) Zahlbr.. [In] LichenIreland. Accessed on 2019-06-25.