Flavoparmelia soredians (Nyl.) Hale
Thallus foliose, rosette-shaped, to 10-15 cm diam., tightly appressed, made of narrow and short lobes, 5-7 mm wide, pleated, thick , with a cardboard texture towards the center, upper surface yellow-greenish, pale grey-yellowish with farinose soralia in patches (and not pustulous), and minute farinose and elongated soredia, possibly forming small heaps. Apothecia rare, 0.5-1 mm, sessile, discs concave, brownish, margin concolorous. Ascospores simple, ellipsoid, 17-18 x 7-8 µm. Photobiont: trebouxioide. Cortex : K-, Medullae : C-, K+ yellow then red, KC+ red, Pd+ yellow-orange to orange. Coastal trends, on siliceous rocks in the aerohaline zone (much more than Flavoparmelia caperata) see: Flavoparmelia soredians forme saxicole and apprently extending its distribution out of the aerohaline zone, seldom on wood or trees see: Flavoparmelia soredians forme corticole. Rather similar to Flavoparmelia caperata but this last species is smaller, with finer soredia and a K- reaction (never red) of the medulla and soralia (reaction often necessary to separate the two species in our prospecting area where they can come in mixture). N.B. In the presence of pseudocyphellae and a red C+ reaction see: Flavopunctelia flaventior.