Physcia clementei ss. str.

    Foliaceous thallus generally circular or oval, 2-5 cm in diameter, firmly attached to its substrate, formed of narrow and branched lobes 0.5 - 1.5 mm wide, pale grey almost whitish in dry weather, very pale glaucous grey in wet weather. This thallus is covered from the centre with small isidioid pustules which can give granular soredia covering almost the entire thallus. Underside dark in the centre, lighter and whitish at the margin of the lobes, rhizines few, concolorous. Upper cortex paraplectenchymatous, medulla white, lower cortex pseudoparenchymatous. Apothecia quite rare, lecanorine, 1-2 mm in diameter, blackish disc, margin sometimes crenate or with isidia. Epithecium brown, hymenium and hypothecium colourless, paraphyses simple or slightly forked at the top, the top cell with a blackish cap. Claved asci with 8 spores and a tholus at the top K/I blue. Ascospores Pachysporaria-type, 1-septate, elliptic 15-20 (24) x 7-11 µm. Pycnidia very rare. Conidia bacilliform. Photobiont chlorococcoides. Cortex and medulla: C-, K+ yellow, KC-, P+/- yellow. Atranorin, matranorin, lecotylin, traces of triterpenoids.

_ The specimens presented here are currently being analyzed and sequencing in the laboratory of Dr. Holger Thüss in Stuttgart (Germany) to obtain a reference DNA barcode because these specimens were collected in Sainte-Anne-la-Palud not far from Brest where the epitype was collected.