Galapagos Species Database

Thallus pale to dark gray when dry, olive green when wet, foliose, loosely attached, thin; outline irregular; lobes folded and contorted when dry, inflated and dome-shaped when wet; surface smooth when wet, indistinctly striate or wrinkled when dry, dull to ± shiny; lacking isidia; apothecia abundant, immersed at the apex of the dome-shaped thallus lobes; disk pale to deep reddish brown, initially concave, soon flattened; margin lecanorine; thalline exciple concolorous and confluent with the thallus, of several thick, paraplectenchymatous cell layers; proper exciple indistinct, in section thin and prosoplectenchymatous; ascospores ellipsoid to broadly ellipsoid, with blunt or ± tapered ends, muriform, 4-5 transversely and 1-2 longitudinally septate, 22-30 x 10-15 µm.

The thalli with inflated dome-shaped lobes and apically immersed apothecia can hardly be confused with any other Leptogium species of the Galapagos. Dry specimens may be mistaken for the plicate thalli of L. phyllocarpum, a species that, however, has a much thicker, strongly rugose thallus and more commonly grows in the dry rather than the humid zones of the islands.