Parmelia submontana

Parmelia submontana is a lichen with a thallus that is loosely attached to the bark of trees, often trailing in well-developed specimens. It has a firm, greenish, mineral-grey thallus that can reach a width of 10–15 cm (4–6 in). The lobes are elongated and linear, measuring up to 30 mm in length and 2–5 mm in width. These lobes are only slightly branched and sometimes weakly channeled. The upper surface is shiny and unbroken, ranging from smooth to slightly wrinkled. 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 develop soralia (powdery patches used for asexual reproduction) that are initially orbicular to linear, often becoming eroded with age. The soredia—tiny grain-like clusters that reproduce the lichen vegetatively—are granular, sometimes appearing almost like isidia (small outgrowths). The lower surface of the thallus is black and sparsely covered with rhizines (root-like structures), which are simple to sparsely branched and measure 1–1.5 mm in length. The species has simple to furcate rhizines, where secondary branches arise obliquely from the axis, unlike the squarrose rhizines found in some other Parmelia species where secondary branches arise perpendicularly. …

Parmelia submontana is widely distributed across Europe, occurring in at least 30 countries and territories. The species has been recorded throughout much of Central Europe, including Austria, Belgium, Switzerland, Czech Republic, Germany, and Luxembourg. In Western Europe, it is present in France, the Netherlands, and the United Kingdom. In Scotland, where it was first recorded in 2002, it often grows on introduced (non-native) tree species and may be an accidental garden import. The lichen's range extends into Northern Europe, with populations documented in Denmark, Norway, and Sweden. In Eastern Europe, it has been recorded in Estonia, Latvia, Lithuania, Poland, Russia, Slovakia, and Ukraine. The species is also present across Southern Europe, occurring in Italy, Slovenia, Greece, and Spain. Additional populations are known from several Balkan countries, including Bulgaria, while the species' range extends into Turkey at its southeastern limit. Although previously reported from Belarus, recent comprehensive studies have failed to confirm its presence there. 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. …