Physconia venusta (Ach.) Poelt
Thallus foliose, more or less rosette-shaped, often very dense and loosely attached to the substratum, 5-15 cm diam., composed of lobes, strap-shaped, narrow, highly branched, overlapping, slightly palmate towards apices, white and powdery, upper surface grey-greenish when moist, bronze to khaki when dry, lower surface pale to dull whitish with rhizines, bottle brush-shaped, black. Apothecia usually numerous, 0.3-0.8 mm diam., disc flat or slightly convex, brown-blackish, brown-chesnut, white powdered, exciple pie edge-shaped, concolourous to the thallus or paler, typically fringed with numerous small foliose lobules giving a daisy or sunflower aspect. Asci with 2-4-6 spores according to our observations. Spores broadly elliptical, brownish, 1-septate, 25-35 x 13-20 µm according to literature, 30-40 x 16-20 µm (but from asci with less than 8 spores). Cortex and medulla : C-, K-, KC-, Pd-. Mediterranean species growing on bark of trees in forests (not too dry). This species is absent in our prospection area and presented here in order to compare with Physconia distorta var. subvenusta often mistaken in Brittany, but the latter has larger, less indented lobes, a greener upper surface and a darker, almost black lower surface. N.B. See Physconia subaquila, sometimes synonymized which grows on rocks and whose lobes are very powdered with white and whose underside is blackish.