Parmelia is a genus of medium to large foliose (leafy) lichens. It has a global distribution, extending from the Arctic to the Antarctic continent but concentrated in temperate regions. There are about 40 species in Parmelia. In recent decades, the once large genus Parmelia has been divided into a number of smaller genera according to thallus morphology and phylogenetic relatedness.
The Parmeliaceae is a large and diverse family of Lecanoromycetes. With over 2700 species in 71 genera, it is the largest family of lichen-forming fungi. The most speciose genera in the family are the well-known groups: Xanthoparmelia, Usnea, Parmotrema, and Hypotrachyna.
Parmelia sulcata, commonly known as the hammered shield lichen or cracked-shield lichen, is a foliose lichen in the family Parmeliaceae. First described by Thomas Taylor in 1836, it is one of the most prevalent lichen species globally, known for its resilience to pollution and cosmopolitan distribution across temperate and cold regions of both hemispheres. P. sulcata forms a circular thallus up to 10 cm (4 in) in diameter, with a glaucous white to grey upper surface and a black lower surface, featuring broadly lobed structures with both marginal and laminal soralia and a distinctive reticulate pattern of pseudocyphellae.
Cetrariella is a genus of foliose lichens in the family Parmeliaceae. It contains three species.
Melanohalea is a genus of foliose lichens in the family Parmeliaceae. It contains 30 mostly Northern Hemisphere species that grow on bark or on wood. The genus is characterised by the presence of pseudocyphellae, usually on warts or on the tips of isidia, a non-pored epicortex and a medulla containing depsidones or lacking secondary metabolites. Melanohalea was circumscribed in 2004 as a segregate of the morphologically similar genus Melanelia, which was created in 1978 for certain brown Parmelia species. The methods used to estimate the evolutionary history of Melanohalea suggest that its diversification primarily occurred during the Miocene and Pliocene epochs.
Melanelixia is a genus of foliose lichens in the family Parmeliaceae. It contains 15 Northern Hemisphere species that grow on bark or on wood. The genus is characterized by a pored or fenestrate epicortex, and the production of lecanoric acid as the primary chemical constituent of the medulla. Melanelixia was circumscribed in 2004 as a segregate of the related genus Melanelia.
Parmotrema is a genus of lichen belonging to the family Parmeliaceae. It is a large genus, containing an estimated 300 species, with a centre of diversity in subtropical regions of South America and the Pacific Islands.
Xanthoparmelia is a genus of foliose lichens in the family Parmeliaceae. This genus of lichen is commonly found in the United States, as well as Australia, New Zealand and Ecuador.
Esslingeriana is a fungal genus in the family Parmeliaceae. The genus is monotypic, containing the single foliose lichen species Esslingeriana idahoensis, commonly known as the tinted rag lichen. It is found in northwestern North America.
Crespoa is a genus of five species of lichen in the family Parmeliaceae. Species in this genus are characterized by having an upper thallus surface that is wrinkled and reticulately ridged to coarsely foveolate.
Emodomelanelia is a lichen genus in the family Parmeliaceae. It is monotypic, containing the single foliose Himalayan species Emodomelanelia masonii.
Notoparmelia is a genus of foliose lichens in the family Parmeliaceae. It includes 18 species that grow on bark and rocks, and are mostly distributed in the Southern Hemisphere. The genus was created in 2014 as a segregate of Parmelia.
Austromelanelixia is a genus of five species of foliose lichens in the family Parmeliaceae. All species are found in the Southern Hemisphere.
Melanohalea zopheroa is a species of lichen in the family Parmeliaceae. It was first formally described in 1977 by Ted Esslinger as Parmelia zopheroa. A year later, he transferred it to the new genus Melanelia, which he created to contain the brown Parmeliae species. In 2004, after early molecular phylogenetic evidence showed that Melanelia was not monophyletic, Melanohalea was circumscribed by lichenologists Oscar Blanco, Ana Crespo, Pradeep K. Divakar, Esslinger, David L. Hawksworth and H. Thorsten Lumbsch, and M. zopheroa was transferred to it. The lichen has a disjunct distribution, as it is found in South America (Chile) and in New Zealand.
Melanohalea ushuaiensis is a species of lichen in the family Parmeliaceae. It was first formally described in 1917 by Alexander Zahlbruckner as Parmelia ushuaiensis. Ted Esslinger transferred to the new genus Melanelia in 1978, which he circumscribed to contain the brown parmeliae species. In 2004, it was moved to the newly created genus Melanohalea. It is endemic to South America.
Melanohalea subolivacea, commonly known as the brown-eyed camouflage lichen, is a species of foliose lichen in the family Parmeliaceae.
Parmelia mayi is a species of foliose lichen in the family Parmeliaceae. It is found in the northern Appalachian Mountains of eastern North America, where it grows on rocks and on the trunks of paper birch and balsam fir. Parmelia mayi is morphologically indistinguishable from Parmelia saxatilis, but is distinct in its distribution, chemistry, and genetics.
Melanelixia ahtii is a species of foliose lichen in the family Parmeliaceae. Found in the United States, it was formally described as a new species in 2016 by Theodore Lee Esslinger, Ana Crespo, Helge Thorsten Lumbsch, Pradeep Kumar Divakar, and Steven Leavitt. The type specimen was collected from the north side of the Columbia River Gorge. Here, at an elevation of 75 m (246 ft) above sea level, it was found in a mixed oak-ponderosa pine forest, growing as an epiphyte on an oak. The species is known from DNA-verified collections in four western US states: California, Idaho, Oregon, and Washington. The species epithet ahtii honours Finnish lichenologist Teuvo Ahti, "for his contributions to understanding diversity in brown parmelioid lichens".
Melanelixia albertana is a species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. First described in 1969 from collections made in Alberta, Canada, it has undergone two taxonomic reclassifications before ultimately being placed in the genus Melanelixia in 2004. The species is characterised by the soralia on the margins of its lobes, a feature that is rare in brown parmelioid lichens. This feature is reflected in its common name, powder-rimmed camouflage lichen. Melanelixia albertana has an unusual Asian-North American disjunct distribution. The widespread presence of Melanelixia albertana across different regions is attributed to the similar climatic and vegetative conditions found in the northern parts of the interior prairies in North America, as well as in the forest steppe and ultracontinental taiga forests of northern Mongolia, Transbaikal, and Yakutia. It occurs in river valley and ravine systems, as well as aspen parkland.
Melanohalea exasperatula, commonly known as the lustrous camouflage lichen or lustrous brown-shield, is a species of corticolous (bark-dwelling) foliose lichen in the family Parmeliaceae. It has a widespread global distribution and is common in both Europe and northern North America. Its thallus can grow up to 5 cm (2 in) in diameter, with marginal lobes up to 5 mm broad. The upper surface is pale olive-green to red-brown, with isidia that are unbranched, inflated, and hollow. It can be distinguished from similar species by the shape and structure of these isidia. The lower surface of the thallus is pale tan to pale brown with scattered, pale rhizines. Apothecia are uncommon, while pycnidia and secondary metabolites have not been observed in this species. The lack of defensive chemicals makes it vulnerable to grazing by slugs and snails. The evolutionary history of Melanohalea exasperatula is linked to major climatic events during the Miocene and Pliocene epochs.
