British distribution: Widespread, probably frequent but overlooked.
A coelomycete with no known sexual stage. Conidia produced in an eustroma, effectively, in this case, a linear aggregation of pycnidia forming under the host epidermis. It is host specific to dead stems of bracken (Pteridium aquilinum), forming groups of short parallel splits (1-3 mm) as the fungus matures and needs to release the conidia. The fungus has a characteristic appearance in the field, but microscopic examination is needed to separate it reliably from other fungi that develop in the bracken epidermis.
A few other fungi with muriform conidia have been assigned to Camarographium but they seem otherwise unrelated and C. stephensii is probably the only known species correctly placed in the genus.
Photographed material: Sandhead, Wigtownshire, 1986.