Phaeographis dendritica (Ach.) Müll. Arg.

    Thallus crustose, 2-4 cm across, thin, most often smooth and glossy, whitish, sometimes tinged yellowish or greenish. Apothecia lirellate, scattered all over the thallus, 1-3 x 0.3-0.5 mm, typically appearing under the thallus then in the open air by tearing it which leaves a false whitish margin forming a bead which is actually the margin of the tear of the thallus, flat and at the same level as the thallus, wide, ends usually acute, seldom simple, straight or sickle or scimitar-shaped, most often feather bunch-like, dendritic or stellate, black, often covered with grey pruine; a section perpendicular to its axis shows the dark carbonaceous margin continues under the hymenium, Ascospores, narrowly fusiform, brown, 5-9-septate, 30-40 x 6-9 µm. C-, K+ yellow > blood red, Pd+ golden yellow. Common, oceanic trends, ubiquitous on bark of deciduous trees. See Phaeographis smithii with the same colored chemical reactions which differs by its slightly shorter lirelles not bordered by a white bead, ascospores 5-7-septate and above all, lirellae section shows a discontinuous exciple below. This species is sometimes parasited by Melaspilea lentiginosa that induces apothecia abortion.