Xanthoria aureola (Ach.) Erichs. forme saxicole de la frange littorale.

    This form is common on rocks of rather protected coasts like the Rade de Brest in the Verrucaria (Hydropunctaria) maura black belt. Thallus pale yellow, yellow, seldom yellow-orange, markedly indented, lobes strap-shaped, branched, discontinuous, lace-like, underlying subtratum visible between lobes, apices upturned, surface rough. Apothecia usually absent. Often parasited and covered with silt in estuaries. N.B. Not to be confused with sterile specimen of Xanthoria parietina that grow in the same habitat but with more greenish thalli, lobes shorter and larger (not strap-shaped), surface smooth.