Porina linearis (Leight.) Zahlbr.

      Thallus endolithic to superficial, thin, continuous and smooth, pinkish, gray-brownish, cream-orange, brown-pink, brick..., so fresh, becoming brown-purplish, gray-purplish in herbarium. Perithecium numerous, more or less immersed in the thallus, scattered over the whole thallus but sometimes in line in the cracks of the rock, 0.1-0.4 µm in diameter at the base, blackish a little hyaline at the beginning then black. Asci not thickened at the apex. Shuttle spores, straight, rarely slightly curved, colorless, 3-septate, 18-25 x 3-5 µm according to the literature, 18-22 (25) x 4-6 µm according to our own measurements. Pycnidia present, immersed in pits, straight or slightly curved pycnidiospores: 3-4.5 x 1-2 µm. Photobiont: Trentepohlia. C-, K + dirty yellow, KC-, P-. Species coming on rocks or large stones of hard limestone, sheltered from direct rains and most often in the shade.