Paralecanographa grumulosa (Dufour) Ertz & Tehler

=Lecanographa grumulosa (Dufour) Egea & Torrente forma grumulosa

    Thallus crustose, usually thick, bumpy, cracked and areolate, slightly farinose, white-greyish, brown-greyish, greyish occasionally tinged lilac or grey-bluish, prothallus brown-blackish, blackish. Apothecia numerous, at first immersed, then sessile, seldom mature excepted in  restricted sections near the margin, mostly packed towards the center, roundish to angular or elliptical, 0.5-2 mm diam., disc flat at first then slightly convex, black but seldom visible due to a thick whitish to white-bluish pruine, exciple thin, distinct soon excluded, greyish. Ascus long mace shaped, 55-65 x 12-17 µm according to our measurements. Ascospores narrowly ellipsoid, 3-4(5) septate, 12-18 x 3-4 µm according to literature ; 13-18 (20) x 3,5-4,5 µm according to us. Thallus C+ red-orange, K-, Pd- (N.B. Attention, it's often due to host's reaction); medulla I-, epithecium KOH grey-greenish and hymenium I+ mahogany. Photobiont: Trentepohlia. Thermophilic trends, occasionally parasite of Roccellaceae, under sheltered overhangs of coastal limestone rocks (or barely acid) and non-lit old walls near the shore, specially chapels. N.B. On walls near the seashore and notably on chapel walls, Lecanographa grumulosa var. hemisphaerica may more frequently be found. The latter has globose apothecia, hardly convex, covered with a thick greyish pruine whose exciple is soon excluded. This variety is a more frequent parasite of the local Dirina and Rocella (see also Lecanographa grumulosa parasite de Roccella phycopsis, Lecanographa grumulosa parasite de Dirina massiliensis forma sorediata, Lecanographa grumulosa parasite de Dirina fallax, Lecanographa grumulosa parasite de Llimonaea sorediata). This species is highly variable and many different taxa may be found according  to the substrata: cement, mortar, siliceous stones, etc., or depending on the growth conditions (parasite or not) and, consequently, many synonyms are in use. On calcareous rocks and on old walls this species is most likely to be confused with Lecanographa abscondita  which is K+/- yellow and above all medulla I+ blue without grey-greenish pigments, apothecia K-, and with Lecanactis dilleniana on siliceaous walls and rocks, which is grey-whitish and Pd+ yellow-orange. N.B. There is no consensus about this species status: is it lichenized or simply a parasite? Forms described here (sometimes considered as varieties, sometimes as species) have little interest to lichen taxonomy. They depend on host and substratum and above all, all intermediate forms may be found.*