Amandinea pelidna (Ach.) Fryday & L. Arcadia écoforme pelidna

    Thallus crustose, potentially forming colonies, more or less cracked, rimose, pale white-ochre, whitish to pale brownish tinged wit red, prothallus sometimes present, inconspicuous, arachnean, only distinct and darker than the thallus in case of mosaics. Apothecia lecideine,more or less sessile, 0.3-0.6 mm in diameter, flat disc becoming convex with age, blackish, margin more or less persistent, thin, black (there are populations in exposed areas which present apothecia very rounded and without a clearly visible margin to the point of making one think of a Verrucaria!). Spores brownish-gray, 1 -septate with walls with a median thickening (giving the impression of a belt or a "corset" around the spores but only those which are very  mature and sometimes of finely warty appearance, 10 -15 x 6.5-8.5 µm according to the literature, 12-15 (18) x 6-9 µm according to our measurements. Black pycnidia frequent especially in certain populations. Photobiont: Chlorococcales. Chemical spot tests negative. Species typically found on siliceous coastal rocks not too acidic and sheltered where it can form colonies. Distinguished from Amandinea punctata by its restriction to coastal and soil habitats, the rimose thallus, median spore wall thickening, and most important from Amandinea coniops of which the thallus is thicker, more yellowish, the prothallus blackish and more distinct and apothecia bigger. N.B. Not to be confused with some Buellia species with positive chemical spot tests.