[4] First described in 1987, it is characterised by a loosely attached, greenish-grey thallus reaching diameters of 10–15 cm (4–6 in), with elongated linear lobes and distinctive powdery structures (isidia-like soredia) for reproduction.

The species shows considerable habitat flexibility, growing primarily on deciduous tree bark in areas with high precipitation and humid microclimates, often near water bodies such as lakes and coastal regions.

"[6] Early lichenologists often struggled to classify this species, commonly treating it as a form or variety of related lichens instead of recognising it as distinct.

Schindler's 1975 summary provided an up-to-date account of the species' distribution and ecology in Europe,[7] noting that P. submontana is primarily found in Mediterranean and South European montane regions.

[8] This rhizine morphology proved to be an important taxonomic character aligning with molecular phylogenetic groupings, helping to resolve some of the historical confusion around the species' relationships.

It was first found and described by Bory de Saint-Vincent from Greece in 1832 as Parmelia contorta (type locality: Peloponnese, Taygetus Pass).

It features small, round to irregularly shaped pseudocyphellae (tiny openings on the surface), which are located both on the lamina (the main, leafy part of the thallus) and along the margins.

These pseudocyphellae, measuring 0.3–1 mm long, quickly become sorediate, with soralia (structures for asexual reproduction) that are orbicular (circular) to linear with an eroded centre as they age.

perlonga, develops the characteristic elongated lobes and is typically greyer in colour, sometimes appearing dusky olive due to numerous ovoid isidia alongside the soralia.

Parmelia submontana could potentially be confused with P. barrenoae as both species possess simple to furcate rhizines and produce soredia.

P. submontana is characterised by distinctive pustulate orbicular soralia (appearing as dactylate or isidioid structures) and long, separate, convolute lobes.

In contrast, P. barrenoae has more superficial laminal soralia and develops revolute older lobes where the lower surface becomes visible from above.

[13] Molecular studies suggest that the genus Parmelia originated during the Early Miocene epoch, approximately 19.5 million years ago.

The species has been recorded throughout much of Central Europe, including Austria, Belgium, Switzerland, Czech Republic, Germany, and Luxembourg.

[15] In Scotland, where it was discovered relatively recently (first recorded in a 2002 checklist) it is noted to occur with introduced tree species and may be an accidental garden import.

[19] Although traditionally considered a Mediterranean and south-central European species, P. submontana has been documented expanding its range northward in recent decades, particularly in Fennoscandia.

[20] It grows on the trunks and branches of various deciduous trees including Acer platanoides, Carpinus betulus, Fagus sylvatica, Malus domestica, Quercus robur, and Tilia cordata, as well as occasionally on conifers such as Picea abies.

In Mediterranean regions, it can be found in communities with Lobaria pulmonaria, L. amplissima, Nephroma lusitanicum, and other species that require high air humidity.

For example, in the Northern Black Forest, documented locations increased from just 5 sites in 1968 to over 70 by 1996, suggesting the species may be benefitting from changing environmental conditions or improved air quality.