Gyalecta truncigena (Ach.) Hepp.

      Thallus very thin, crustose, sometimes barely visible, smooth or a little rough, pale grayish, pale greenish. Apothecia scattered throughout the thallus, at first immersed in the bark of the substratum and then slightly superficial, 0.2-0.7 mm in diameter, concave disc, cream, cream-orange, cream-brownish, may turn brownish to blackish in old age, thicker margin paler, sometimes at first covered with star-shaped shreds of the thallus. Asci with 8 spores, 70-90 x 15-25 µm according to our measurements. Spores broadly fusiform, hyaline, muriform with 5-7 transverse and 1-2 longitudinal partitions delimiting 8-12 cells, 17-28 x 5-9 µm according to the literature; 16-25 x 7-9 µm according to our measurements. Photobiont: Trentepohlia. C-, K-, KC-, P-. Rather rare (or unnoticed) species found on the bark of trees, especially oceanic forests.

N.B. Gyalecta flotowii very similar to smaller, subspheric spores.