Bracken Map Fungus

Bracken Map (Rhopographus filicinus) is a common and widespread species of fungus that is mainly found in the UK, with some records from mainland Europe, including France, Sweden, Germany, and north to Scandinavia.

UK distribution map of Rhopographus filicinus © NBN Atlas

Not much is known about the fungus, but it is characteristic in its appearance as it forms linear black marks on the petioles (stem) of living Bracken (Pteridium aquilinum) plants and becomes more obvious once the plants have died. As such, it is most noticeable in autumn when the Bracken plants turn brown and die.

Rhopographus filicinus on the stem of a Bracken plant on the UEA campus.

Unfortunately I couldn't find any more information about the ecology of Bracken Map Fungus, so that'll have to do.