• Arthonia radiata (Pers.) Ach.
Arthonia radiata
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This common crustose lichen forms small (about the size of a fingernail), thin, pale grey or pale brown stains on young bark with crowded, irregularly sprinkled star or Z-shaped, black discs. It frequently grows in the spaces between other bark lichens and is a pioneer lichen of well-lit smooth bark. It is especially common on twigs and branches and on the main stems of newly planted trees in parks and gardens.

Key characteristics

  • Contrasting black, fuzzy, star-shaped discs on an extremely small, pale grey thallus
  • The small crusts can be found growing between larger crustose lichens on tree branches.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Arthonia radiata (Pers.) Ach.. [In] LichenIreland. Accessed on 2018-08-16.