Species: Parmotrema crinitum
Photos: On Alder trunks. Glengarrif woods, Cork, SW Ireland.
Loosely attached pale-grey thallus. Incised, over-lapping lobes with distinctive mix of black cilia and coralloid isidia on margins and surface. Underside black with rhizines in centre and brown, bare margins. Apothecia very rare, brown discs with isidiate margins.
Medulla: K+ yellow, P+ yellow-orange, UV-
'Old forest' indicator species, well-lit mossy rocks, tree trunks.
Most frequent in W Ireland.
Similar: Parmotrema perlatum. Sorediate, isidia absent.
Parmelinopsis horrescens. Smaller thallus, medulla K-
Parmotrema crinitum. Glengarriff woods, Co.Cork. January 2009 and April 2010