• Opegrapha rufescens Pers.
Opegrapha rufescens
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(Map updated: 11 August 2009)

This ‘not difficult to identify’, crustose epiphytic lichen, grows on relatively smooth, ±basic bark such as that of ash, sycamore or elm. Those used to seeing Opegrapha colonies on trees will immediately notice that this is something entirely different, as the immersed discs (squat lirellae) of this species are bordered by a striking white margin (like a halo) which distinguishes it outright. In Ireland, the species is thinly scattered.

Key characteristics

  • Discs (lirellae) immersed, also compressed, and ringed by a neat white margin which is utterly distinctive
  • Spores three-septate, curved, spindle-shaped.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Opegrapha rufescens Pers.. [In] LichenIreland. Accessed on 2019-01-20.