Porina leptalea (Durieu & Mont.) A. L. Sm.
Thallus crustose, thin and superficial (coat-like), smooth to minutely rugose, greyish, brownish, occasionally greenish to olive-green. Perithecia small, rounded, wart-shaped, partially immersed in the thallus, 0.1-0.3 mm diam., pale brown-pink, pale brown, pale brown-orange. Ascospores colourless, shuttle-shaped, 3-septate, 15-25 x 3-5 µm. Pycnidia present, 0.1 mm diam., pink-orange. Photobiont: Trentepohlia. Chemical spot tests negative. On bark of deciduous trees, more seldom on coniferous, sometimes on damp shaded rocks, and on leaves notably of Buxus. This species probably is common but somewhat understated owing to its small size and its drab aspect. N.B. See Porina lectissima when it comes to wet rocks along the edges of shady rivers, but this last species has larger perithecia and spores.