Hypotrachyna taylorensis (M.E. Mitch.) Hale forme corticole.

     Foliose thallus arranged in a rosette loosely attached to the substrate, formed of lobes and sometimes small leaflets overlapping towards the center (appearance of waves on a beach), 2-6 mm wide, cut and sinuous with rounded and downward-turned apexes. Fragile upper surface with eroded areas and spotted with whitish spots, bluish-grey in wet weather, ash-grey in dry weather, neither isidia nor soralia according to British authors (but with sometimes white soralia according to French authors!), sometimes with schizidia leaving whitish then brownish and finally blackish scars when falling. Shiny underside, black with branched rhizines. Very rare apothecia, 3-5 mm in diameter, brownish disc, crenate margin. Simple spores, hyaline, broadly elliptical, 9-14 x 6-10 µm. Photobiont: Trebouxia. Cortex: K+ yellow, medulla: C+ carmine pink, K-, KC+ carmine red, P-, UV+ bluish white. Uncommon species with oceanic tendencies, found in the moss on the trunks or large branches of forest trees.

There is a saxicolous form, see: Hypotrachyna taylorensis forme saxicole.

Cf. Hypotrachyna revoluta which is sorediate.