Enchyllium tenax (Sw.) Gray var. tenax

    Thallus foliose, made of heaps of lobes, more or less rosette-shaped, 5-10 cm diam., lobes dark brown-olive, markedly swollen when moist, dark brown, wrinkled, membrane-like, thin when dry, occasionally presence of globular isidia. Apothecia often numerous, up to 2-3 mm diam., located near the rims or dispersed at the lobes' surface, disc flat, then convex, brown-black, brown-red, with a narrow full, smooth, concolourous and rarely granular margin. Ascospores broadly ellipsoid, 3-septate or submuriform, 15-25 x 6-10 µm. Pycnidia present. Photobiont: Nostoc. A fairly common species (in the broas sense), not especially maritime, very variable depending on its habitat and of which several varieties have been made (of sometines limited interest because there are intermediates!):

_ Enchylium (Collema) tenax var. tenax: growing on mossy rocks that are more or les calcareous or slightly acidic, old walls, calcareus dunes, etc., in the areohaline zone in particular, usually very fertile.

_ Enchylium (Collema) tenax var. ceranoides: growing on the compacted soil of calcareous dunes, less spread out and more hemisphaerical upright lobes, generally sterile.

_ Enchyllium (Collema) tenax var. vulgare: growing on more or less mossy calcareous rocks, small fertile variety with short and very swollen lobes.