Anaptychia palmulata (Michx.) Vainio ss. auct. am.

    Foliose thallus firmly attached to the substrate, 8-10 cm in diameter, formed of dissected lobes 1-2.5 mm wide. Upper surface finely powdered with whitish, especially at the tips of the lobes, olive-brown in dry weather, greenish in wet weather, underside fibrous, whitish, with simple whitish rhizines. Apothecia more or less abundant, lecanorine, 2-4 mm in diameter, disc dark brown, margin sometimes with small lobules. Cortex: K-, KC-, C-, P-; medulla: K-, KC-, C+/- yellow, P-. Continental and northern species occurring on tree bark, wood or rocks.

N.B. The North American species presented here seems different from what is attributed to Anaptychia palmulata Cf. in France...