Romjularia lurida (Ach.) Hafellner & Türk

    Thallus squamulose, squamules up to 5 mm wide, more or less intricated, apices rounded, convex and twisted, crust-forming on the substratum, brown-greenish when moist, dark brown, brown to brown-olive when dry, lower surface blackish. Apothecia leceidine, clustered, up to 1 mm diam., disc flat then convex, blackish to dark brown, exciple concolourous often excluded when mature. Ascii 8-spored, 60-90 x 18-25 µm according to our measures. Ascospores colourless, broadly ellipsoid, simple, 9-11 (15) x 6-8 µm or 11-14 x 6-7 µm according to the literature, 11-15 x 5-7 µm according to our measures. Pycnidia, black more or less sessile, punctiform towards mobe margins. Photobiont: Trebouxioid. Chemical spot tests negative. Not especially maritime, in cracks and crevices with soil on humid surfaces of calcareous or slightly acid rocks, sometimes on grounds of dunes enriched with shell debris.

N.B.  Microscope observation is often required in order to distinguish specimen of this species growing near the seashore from  Solenopsora holophaea which seldom grows on calcareous rocks, and is characterized by lip-shaped squamule apices and faintly lecedidine apothecia with paler exciple and above all 1-septate ascospores.

N.B. Cyanobacteria belonging to the Gloeocapsa genus have been observed on fresh samples, but their role has not yet been clarified: accidental or involved into lichen metabolism?