Peltigera praetextata Scaly Dog-lichen

A large, foliose lichen which is very similar to Peltigera membranacea but the thallus surface is less wrinkled and, notably, often with abundant (sometimes sparse) marginal squamules (schizidia) on the upper surface and smooth, simple rhizines. It grows predominantly on mossy trees, especially Ash (Fraxinea excelsior), old oak trees (Quercus spp.) and Hazel (Coryllus avellana), but also on logs and rock, in sheltered locations in the west and north of Britain. It is an important component of cool, humid, temperate forests such as the British Atlantic woodlands that occur in the west of Britain. It is found throughout Wales and is scattered in West Glamorgan where it occurs along the south Gower coast and in the humid forests of Neath and Afan valleys in Neath Port Tabot. It is probably under recorded here and mistaken for Peltigera membranacea when schizidia are scarce or absent.

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