• Parmotrema arnoldii (Du Rietz) Hale
Parmotrema arnoldii
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(Map updated: 11 August 2009)

This rather elegant foliose lichen of tree branches in undisturbed woodland or entangled among Calluna in valleys near the coast is closest in appearance to P. perlatum but differs in chemistry, and in the black marginal cilia which can be up to 5mm long (compared with 12mm long in P. perlatum). Lobes are loosely attached and the medulla is KC+ red (KC + yellow-orange in P. perlatum). In Ireland, the species is uncommon and has a predominantly west coast distribution.

Key characteristics

  • Thallus more loosely attached than P. perlatum and with long, black marginal cilia
  • The medulla tests KC+ pink or red.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Parmotrema arnoldii (Du Rietz) Hale. [In] LichenIreland. Accessed on 2019-01-19.