: Arthonia radiata.

Arthonia radiata is a common pioneer species on smooth bark of deciduous trees. It is characterized by highly variable, irregularly maculate to branched or star-shaped apothecia on often a mosaic forming white or light grey thallus with trentepohlioid photobiont. The colorless spores are 3-septate and lack an enlarged apical cell.

Arthonia radiata (Pers.) Ach.
Creative Commons Attribution | Andreas Frisch | NTNU Vitenskapsmuseet | Håkon Holien | NORD Universitet
Kart. Utbredelse i Norge.