• Opegrapha xerica Torrente & Egea
Opegrapha xerica
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(Map updated: 11 August 2009)

This species grows on dry acid bark such as that of oak and yew. The thin thallus is grey, but sometimes a hint of green may be glimpsed. Discs (lirellae) are mostly simple and expanded, the spores three- to five-septate with an enlarged upper cell. The greenish colour of the epithecium in a squash of the disc is significant. It is easily overlooked for O. varia which has a brown epithecium. In Ireland, the species is thinly scattered.

Key characteristics

  • Grey thallus with greenish tinge: dry, acid bark of old trees
  • The lirellae are expanded discs like those of O. varia but have three- to five-septate spores and a greenish epithecium.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Opegrapha xerica Torrente & Egea. [In] LichenIreland. Accessed on 2019-05-23.