Ramalina fastigiata (Pers.) Ach.
Thallus tufted, often half-spherical, 2-5 cm tall, more or less erect, made of short branches, 2-5 mm wide, pleated and wrinkled, sometimes excavate, notably towards apices near apothecia, medulla hollow, soralia, isidia and pseudocyphellia absent, upper and lower surface concolourous, pale grey-greenish, pale grey-yellowish, pale greyish. Apothecia numerous, at lobe apices, often at the same level, disc concave, then flat and occasionally convex, concolourous to the thallus or very pale beige-pink. Ascospores broadly ellipsoid, slightly kidney-shaped, 1-septate, 12-17 x 5-6 µm. Photobiont: Trebouxioid. Chemical spot tests negative. Common, on twigs of trees in humid and well-lit areas, often together with other Ramalina species very rare on rocks.
N.B. Near the seashore, not to be confused with Ramalina calicaris of which the lobes are caniculate and the ascospores straigth, and with Ramalina fraxinea which the apothecia are cup-shaped at first, and mainly lateral, arranged in several levels.
N.B. In very windy areas by the sea, beware of smaller Ramalina pusilla, with apothecia remaining concave and poorly developed and especially K+ red (slow).
N.B. On the branches of seaside shrubs subject to sea winds and spray, see: Ramalina fastigiata forme ramicole and Ramalina fastigiata forme de la zone aérohaline