The lichen has a
foliose (leafy)
thallus, that is either
corticolous (bark-dwelling),
foliicolous (leaf-dwelling), or occasionally
saxicolous (rock-dwelling). It forms
rosettes of in diameter. The are irregularly to somewhat branched. These lobes are discrete in peripheral parts of the thallus, and towards the centre. The upper surface of the thallus is pale greyish-green when fresh and dry, turning salad-green when moist, and gradually turning
chestnut brown after storage. The upper
cortex is 25–40
μm thick. are common along the margins, and the is composed of more or less spherical cells. The
medulla is mostly white, with a dark brown lower part.
Apothecia are absent, sparse, or common, with a rufous-brown . The
hymenium is colourless and intensely IKI+ blue. Proper are
hyaline, non-
septate, and regularly elongate to
ellipsoid. ==Chemistry==