Galapagos Species Database

Thallus gray to dark black when dry, blackish when wet, foliose, adnate, thick, swelling considerably when wet; outline irregular; lobes distinct, narrow and elongated, frequently anastomosing; surface rugose, irregularly contorted and folded (plicate); lacking isidia, but sometimes lobulate along the thallus lobes and apothecial margin; apothecia common, distinctly stalked, submarginal, expanded; disk pale to deep reddish brown, initially concave but soon flattened; margin lecanorine, strongly folded (lamellate), occasionally lobulate, concolorous with the thallus, with a broad paraplectenchymatous outer thalline exciple and an inner, indistinct, thin, prosoplectenchymatous proper exciple; ascospores ellipsoid, muriform, 3-5 transversely septate, 1 longitudinally septate, 22-33 x 10-14 µm.

Because of its stongly convoluted, folded apothecial margins, superficially similar to Physma byrsinum, which however has simple, ellipsoid spores and in Galapagos has only been found in extremely humid habitats.