Order: Lecanorales Family: Physciaceae
Species: Heterodermia japonica
Photos: On Salix. Killarney, Co. Kerry, SW Ireland.
Identified by John Douglass
Pale grey thallus (greener when wet), usually forming spreading rosettes. Flat, radiating lobes with lip-shaped soralia and short black cilia on the tips. Apothecia very rare, discs red-brown with crenulate or sorediate margins. Lower surface white with brownish hyphae. Thallus K+/- yellow, C-, KC-, P-
Occurs on mossy trunks and branches of Willow, Oak, Hazel and Ash in undisturbed woods and sallow carr. Also found on coastal turf.
The name Heterodermia japonica has been wrongly applied to specimens from Britain and Ireland. These should be known as Heterodermia obscurata.
Heterodermia japonica. November 2010