LichenIreland
  • Trapelia coarctata (Sm.) M.Choisy
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Trapelia coarctata
© Mike Simms
Trapelia coarctata
© Mike Simms
Trapelia coarctata
© Mike Simms
Trapelia coarctata
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(Map updated: 11 August 2009)
Trapelia coarctata
© Mike Simms
 

This small, crustose lichen is very common on the tops of siliceous rocks and boulders, including artificial substrata. The thallus is an agglomeration of scattered, grey (sometimes pinkish) squamules, with red-brown discs. It can be variable, but may be separated from other Trapelia species by the squamulose (not crustose) thallus and lack of soralia (powdery patches). A dab of C (Calcium hypochlorite) will turn the thallus red.

Key characteristics

  • Trapelia species are best confirmed using the C test
  • The tiny clusters of squamules, often surmounted by pink discs are diagnostic.

Original text submitted by Simon Davey

 
 Simms, M. J., (2016). Trapelia coarctata (Sm.) M.Choisy. [In] LichenIreland.
http://www.habitas.org.uk/lichenireland/species.asp?item=19104 Accessed on 2018-09-22.