• Clauzadeana macula (Taylor) Coppins & Rambold
Clauzadeana macula
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Look for this crustose lichen on large granitic outcrops or boulders. The thallus minutely cracked into tiny red-brown areoles over a black prothallus giving the whole a mysteriously dark jizz which lure the searcher. The tiny aspicilioid discs are immersed in the thallus. If you expose the medulla then try the Pd+ red test. Claurouxia chalybeioides is larger and greener and is drawn to damper rock surfaces. In Ireland, it has been recorded from the south and north-west.

Key characteristics

  • Thallus red-brown on a black prothallus, minutely cracked; discs aspicilioid
  • Looks at first like a blackish stain on the rock, medulla Pd+ red; on well-lit granitic rocks.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Clauzadeana macula (Taylor) Coppins & Rambold. [In] LichenIreland. Accessed on 2018-07-23.