Physcia clementei (Sm.) Lynge

    Thallus foliose, rosette-shaped, 2-5 cm diam., lobes 0.3-0.6 mm wide, apices crenulate and fan-shaped, upper surface pale blue, white-greyish, center with numerous soralifer isidia, more or less in small piles, easily broken down, papilla-like to verrucose, and giving soralia by breaking down or erosion; lower surface dull whitish. Apothecia rare, 0.5-1.5 mm diam., disc blue-blackish, blue-purple, more or less pruinose, thalline exciple thick and crenulate. Ascospores brown, broadly ellipsoid, 1-septate, , 15-20 x 8-10 µm. Cortex and medulla : C-, K+ yellow, Pd+ yellow. Rather rare in our prospection area, on tree trunks in well-lit locations, seldom on rocks. N.B. The epitype of this species of W. France, English Channel Islands, S. England, Wales and ireland was found in 1931 in Brest railways station (Brest-Le Conquet line).*