Lasallia brigantium (Zschacke) Llano
Umbilicaria brigantium Zschacke
Thallus foliose, monophyllous, umbilicate, attached by a stout more or less central umbilicus, potentially forming large colonies, upper surface densely pustulate, pustules rise limited to a few mm, slightly cotonny, whitish, pale greyish, without coralloid isidia (to the contrary of Lasallia pustulata) but sometimes with some squamulose isidia, lower surface without rhizines, blackish, minutely cracked, truffle-like. Apothecia most often numerous, notably towards the margin, 0.5-2 mm diam., immersed at first, becoming erumpent but not sessile, disc flat, blackish, true exciple uneven, concolourous to the thallus. Ascii 1(2)-spored, broadly urn-shaped, 75-100 x 30-45 µm according to our measures. Ascospores, minutely muriform,turning to brown when mature, 50-90 x 30-40 µm, 50-85 x 32-45 µm according to our measures. Photobiont: chlorococcoid. Mediterranean species, thermophile, nitrophile, on siliceous rocks near the seashore or in lowlands. Restricted to Corsica and Sardinia.