Peltigera polydactylon (Neck.) Hoffm.

    Thallus foliose, to 10-15 cm across, made of lobes 1-1.5 cm wide and 3-6 cm long, up-turned at apices, somewhat wavy or crispy, upper surface smooth, glossy to bright sometimes with a whitish micaceous coating towards the margins, grey-brownish when dry, brownish to grey-olivaceous when moist, lower surface with a well-developed network of veins, flattened, dark brown towards the center, ochraceous towards the margins, with a typical whitish background surface in the more or less rounded to elongated interstices, rhizines more or less fasciculate, brown-blackish. Apothecia to 0.5-1 cm diam., more or less folded to almost cylindrical, located at tip of folded fertile lobe, vertically erected (1-3 cm tall), suggesting a finger with its varnished nail (giving its name to the species), disc red-orange turning brown-red. Ascospores acicular, 3-septate, 50-70 x 2,5-5 µm. Photobiont: Nostoc. Rare, on mossy grounds and rocks, notably in old humid woodlands. See Peltigera hymenina, much more common of which the apothecia are more orange and arising directly from fertile lobe margins, and not digitate.*