Lichens marins - Gyalecta flotowii Körb.

Gyalecta flotowii Körb.

Gyalecta flotowii Körb.

Gyalecta querceti Nyl.

Description

Thallus crustose more or less smooth, relatively thin and sometimes inconspicuous, grey-greenish, grey-yellowish. Apothecia urceolate then slightly sessile, more or less immersed in the bark, 0.2-0.4 mm in diameter, disc concave, beige, light brown, cream-orange, light brown-orange, absence of thalline rim, true exiple, smooth to sometimes a little crenellated, cream-orange a little transparent (N.B. Different appearance depending on whether this species is wet or dry, see the photographs). Spores colorless, broadly elliptical to ovoid or nearly spherical, submural with 1-3 longitudinal septa and 3-4 transverse septa, and 6-7 cells, 9-14 (18) x 6-9 (11) µm according to literature; 12-18 x 7-8 (10) µm according to our measurements. Paraphyses simple, septate, regular and not swollen at the top. Photobiont: Trentepohlia. No significant color chemical reactions. Uncommon species (but unspectacular and to be specially sought) growing on the bark of deciduous trees but sometimes also of conifers in woods and oceanic forests.

N.B. Very similar species to Gyalecta truncigena which has larger and more elongated spores with more cells.