Paralecanographa grumulosa (Dufour) Egea & Torrente forma hemisphaerica

    Differs (theoretically) from Lecanographa grumulosa forma grumulosa by its regular parasitism (at least at the start) and its macroscopic aspect. At first the apothecia, markedly globose, invade the center of the host thallus and progressively spread over. At the end only the black host prothallus remains visible. Apothecia slightly convex at first, disc blackish, becoming markedly convex, then globose, exciple concolourous excluded at the globose stage, covered with a thick greyish pruine, masking the disc. At the end, the host thallus is entirely absorbed, hidden by the parasite thallus and apothecia of this form. Ascospores longly ellipsoid, (2) 3 (4)-septate, 12-18 (20) x 3-4 µm according to our measurements. This variety, often melted with the form type Lecanographa grumulosa forma grumulosa, may be found on walls of old chapels near the seashore as a parasite of almost all species in this environment: Dirina massiliensis f. sorediata, Llimonaea sorediata, Roccella phycopsis, Dirina fallax, etc.

N.B. The 'washed' apothecia, devoid of pruine, are intense black and strongly contrast with the thallus.