Montanelia predisjuncta

Montanelia predisjuncta is a species of saxicolous (rock-dwelling) foliose lichen in the family Parmeliaceae. The lichen forms small rosettes of narrow, olive-brown to dark brown lobes that grow tightly pressed against rock surfaces in mountainous areas. It was originally described from Japan and has since been recorded from China and Russia, though some genetic studies suggest it may not be distinct from the more widespread Montanelia disjuncta. The species is characterized by its lack of powdery or granular reproductive structures, the presence of irregular pale markings on its upper surface, and its production of perlatolic and stenosporonic acids.

Taxonomy

Montanelia predisjuncta was described in 1977 by Theodore Lee Esslinger as Parmelia predisjuncta, based on saxicolous material collected on rock from Azusayama in central Japan (Shinano Province) at 1,400–1,500 m elevation. In the protologue, it was presented as closely related to P. disjuncta but consistently lacking soredia and containing perlatolic and stenosporonic acids. Esslinger also argued that it should not be treated as a "species pair" with P. disjuncta because the two differ in several additional characters. He reported that it had sometimes been mistaken for P. stygia, but separated it by differences in pseudocyphellae and by secondary chemistry, noting that the chemical races of P. stygia did not match P. predisjuncta in containing depsides.

The species was later treated in Melanelia as Melanelia predisjuncta. Divakar and co-authors segregated the Melanelia disjuncta group as the genus Montanelia using multilocus phylogenetic analyses supported by morphology and chemistry, and they made the new combination Montanelia predisjuncta.