: Arthonia didyma.

Arthonia didyma is a common species on smooth bark of deciduous and coniferous trees in humid forests and woodlands throughout southern and central Norway. It is characterized small dark orange-brown to brown-black apothecia on a pale fawn or grey olive thallus with a trentepohlioid photobiont. The 1-septate spores are brown and warted when old.

Arthonia didyma Körber
Creative Commons Attribution | Andreas Frisch | NTNU Vitenskapsmuseet | Håkon Holien | NORD Universitet
Kart. Utbredelse i Norge.