Degelia cyanoloma (Schaer.) H. H. Blom & Lindblom
Pectenia atlantica (Degel.) P. M. Jorg. morpho. cyanoloma
Thallus, irregular rosette forming, 10-15 cm max. width, made of lobes, ribbed by minute ridges -visible only with magnifying lens- both radially and concentrically (oyster shell pattern), apices slightly rounded, isidia absent or uncompletely developed toward the center, upper surface lead grey-blue when wet and pale grey-brown, blueish when dry, lower surface black, prothallus thin, fringed blue-black. Apothecia in low number, scattered all over the thallus, dark brown-red at first, soon brown-black to black, pale thin exciple, usually persistant. Ascospores and chemical spot tests as Degelia plumbea except that, according to our measurements, the size of ascospores is 15-20 x 6-9 µm. Photobiont : Nostoc. Chemical spot tests negative. Hyperoceanic species growing on mossy trees of mild, humid woodlands near the sea. N.B. Very close to and confused for long with Degelia plumbea and considered by some authors as a hyperoceanic variant. Degelia cyanoloma differs notably by its large size, its lobes displaying more pronounced ribbed and less abundant apothecia soon brown or even blackish, suggesting Degelia atlantica s. str., as admitted by some authors.