Peltigera collina (Ach.) Schrad.

    Thallus foliose, to 5-15 cm across, lobes randomly dispersed and appressed, 0.5-2 cm wide, margins undulate almost entirely sorediate, soralia granular, grey-bluish, upper surface smooth, except sometimes towards the margin, grey-brownish, grey-bluish when dry and grey-olive or grey-green when moist, lower surface whitish to pale cream-ochre with whitish to brownish flattened veins (brown in herbarium), from where arise rhizines, simple or in tufts, concolourous. Apothecia scarce, saddle-shaped or rounded, dark-brown. Ascospores fili-fusiform, 3-5-septate, 40-70 x 4-5 µm. Chemical spot tests negative. On mossy tree trunks (Populus, Fraxinus, Alnus) in humid areas. Not to be confused with  Nephroma parile  characterized by its lower surface devoid of veins, and with Sticta limbata of which cyphella are present on the lower surface.*