Vahliella leucophaea (Vahl.) P. M. Jorg.

   Thallus crustose, of rounded and turgid squamules, to 2 mm diam., smaller and discrete at margin, often becoming ± imbricate at centre, forming a rather thick, cracked-areolate crust with a black hypothallus usually visible within cracks, squamules greyish, grey-brown to brown-blackish according to hydration. Apothecia usually numerous, to 1 mm diam., disc plane then slightly convex, brown-black, brownish, thalline exciple often indistinct, sometimes unevenly developed. Ascospores colourless, without a perispore, containing several oil droplets suggesting a pluriseptate ascospores, 15-17 x 5-6 µm. Photobiont: Nostoc. Chemical spot tests negative. Grows in fissures of sheltered  moist rocks near the seashore. Highly variable; requires additional work.*