Heterodermia speciosa (Wulf.) Trevisan
Heterodermia obscurata p.p.
Heterodermia japonica p.p.
Thallus shaped as a rosette of 2-4 cm diam., formed by radiant and quite notched lobes, 1-2 mm wide, upper side cream, pale cream-ochre when dry, glaucous to grey-greenish when wet, well applied on substratum, with soralia apical and labriform, whitish to pale grey-bluish, a bit floury ; lower side cream and slightly brownish with simple rhizines at margins, black. Non fertile under our climates elsewhere with some rare apothecia with a dark brown disc and a more light and crenelated exciple. Ascospores ellipsoid, brown, 1-septate, 20-30 x 12-18 µm according to literature. Cortex and medulla C-, K+ yellow, KC+ yellow. Rare species of Lobarion pulmonariae growing on mossy trunks on tree in wet temperate oceanic forests. Cf. Heterodermia obscurata of which the lower side of thallus is colored ochre-orange (at least partially) and Heterodermia subneglecta, lighter and from exposed coastal heaths.
N.B. The highly variable European taxa of this genus are interpreted very differently by the authors, so this is a provisional interpretation. In order to clarify the subject, the specimen presented here are subject to sequencing in an attempt to clarify their identification for the moment based on unreliable and quantitative characters (orange spots on the underside, white-grayish coloration or creepy, etc.).
N.B. It seems that Heterodermia speciosa ss. stricto is a species absent from France and that it is here specimens of Heterodermia subneglecta corticole form.