Gyalolechia fulgens (Sw.) Søchting, Fröden & Arup =Fulgensia fulgens (Sw.) Elenkin

   Thallus squamulose, rosette-like, up to 4 cm diam., marginal lobes distinct, clearly differentiated, made of convex squamules, 1-2 mm wide, indented and appressed, canary-yellow, bright yellow, center whitish due to schizidia production exposing the white medulla. Apothecia more or less abundant, 1-1.5 mm diam., disc plane, bright orange, margin pale yellow to yellow-orange soon excluded (fertile specimen resemble to fried eggs and are easily recognizable). Ascospores colourless, simple (but sometimes artefactually 1-septate shaped under microscope), variable in shape, pyriform, ellipsoid, clavate,  9-12 x 3-5 µm. Photobiont: Trebouxia. Thallus and apothecia : K+ purple. Not especially maritime, but not rare on mossy soils of calcareous and dry dunes near the seashore (this species is a good indicator of calcareous dunes). See Fulgensia fulgida, mediterranean thermophilic calcicolous and saxicolous species with a more yellow-greenish thallus and numerous redder apothecia, and above all larger and markedly clavate ascospores. *

N.B. This species shares the same photobiont (Trebouxia Cf. asymmetrica) as Toninia sedifolia that makes a good substratum to the Fulgensia thallus. This complex phenomenon has been described in BECK A., KASALICKY T., RAMBOLD G. 2002. Myco-photobiontal selection in a Mediterranean cryptogam community with Fulgensia fulgida. New Phytologist, 153: 317-326. Some pictures below illustrate this phenomenon.*