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
|
Andreas Frisch
|
NTNU Vitenskapsmuseet
|
Håkon Holien
|
NORD Universitet
