Description: 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 Identification Features:

• 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

Distribution Map from NBN: Arthonia radiata at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Arthonia radiata at iNaturalist World Species Observations database.