Parmotrema perlatum Powdered Ruffle Lichen

A very common, epiphytic lichen, often on trees or shrubs with acidic bark. It is found throughout West Glamorgan, commonly on oaks, willows and hawthorn. The dark underside to the thallus and the occurence of black, eyelash-like cilia, which are often visble along the edges of the thallus lobes, are prominent characters. Clusters of powdery soralia are frequently found along the upturned edges of the thallus lobes. It is sensitive to sulphur dioxide pollution and has undergone a significant increase in its abundance and distribution in many parts of the country.. 

Listed under Parmelia perlata by Alan Orange in Flora of Glamorgan (Wade et al, 1994).