• Caloplaca flavorubescens (Huds.) J.R.Laundon
Caloplaca flavorubescens
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(Map updated: 11 August 2009)

This rare epiphyte forms grey or greenish, yellowy crusts on the bark of wayside trees with bright orange discs usually visible. It grows on the platy roots and lower trunks of trees such as ash, oak and sycamore often in isolated situations in pastures and parklands. It is tolerant of dust but over-enrichment kills it. It has been recorded from Counties Longford, Fermanagh and Tipperary. Field trees not being replaced when they die is also a contributory factor to its loss.

Key characteristics

  • Bright orange discs (to 3mm diam.) against a greyish-green thallus with a yellowy tinge
  • It does not occur on twigs and branches so should not be confused with smaller mosaic-forming lichens such as C. ferruginea.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Caloplaca flavorubescens (Huds.) J.R.Laundon. [In] LichenIreland. Accessed on 2020-05-26.