Heterodermia subneglecta Elis
Heterodermia obscurata auct. europ. non (Nyl.) Trevis p.p.
Heterodermia japonica (M. Sato) Swinscow & Krog ss. Moberg p.p.
Thallus reaching up to 10 cm across, lobate, lobes 1-2 mm wide, marginal lobes recurved, fringed with short black cilia and more or less globular soralia at margins, upper surface very pale white-greyish, pale white-greenish when dry, pale greenish-white and glaucous when moist, lower surface creamy-white. Apothecia very rare, disc dark brown, margin crenulate and sorediate. Ascospores broadly ellipsoid, 1-septate, 21-31 x 12-17 µm. Photobiont: chlorococcoid. C-, K+ yellowish, KC-, Pd-. Oceanic species, grows on soils at the base of rocks or in heaths of very exposed aerohaline heathlands, sometimes on acide rocks ; rare, its observation requires a targeted search (DO NOT SAMPLE).
N.B. Synonymy of Heterodermia is peculiarly confused and numerous taxa have been diversely interpreted by authors ! What we present here under the name Heterodermia subneglecta was formerly described as Heterodermia japonica or Heterodermia obscurata, these names encompassing all species growing on tree barks in oceanic forests.
NB The specimens presented here are currently under study and analysis, according to the first results they will have to be renamed because it is probably an endemic taxon of Pointe de Bretagne, of the Channel Islands, of the Isles of Scilly and of English Cornwall.