Description: This not uncommon, crustose epiphyte has a rather distinctive habitat: the small twig and branch nodes of willow trees in sallow swamp or ‘carr’. While it also grows on other hosts, sallow is the host to target. This species has a thin, whitish, generally insignificant thallus with a prominent cluster of reddish-brown to dark brown, almost black, discs (0.2-0.5mm diam.). It is scattered in Ireland but is more frequent around the loughs of the north and west.

Key Identification Features:

• The habitat and clustered, dark brown to almost black fruits on twigs, often associated with Lecanora jamesii serve to suggest this species
• It can be confirmed with certainty by microscopic analysis: spores simple, ellipsoid, thick-walled (17 x 9 µm).

Original text submitted by Simon Davey

Distribution Map from NBN: Japewiella tavaresiana at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Japewiella tavaresiana at iNaturalist World Species Observations database.