Parmelia is a genus of medium to large foliose 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.
Myelochroa is a genus of foliose lichens in the family Parmeliaceae. They are commonly known as axil-bristle lichens. It was created in 1987 to contain species formerly placed in genus Parmelina that had a yellow-orange medulla due to the presence of secalonic acids. Characteristics of the genus include tightly attached thalli with narrow lobes, cilia on the axils, and a rhizinate black lower surface. Chemical characteristics are the production of zeorin and related triterpenoids in the medulla. Myelochroa contains about 30 species, most of which grow on bark. The genus has centres of distribution in Asia and North America.
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 characterized 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 compounds. Melanohalea was circumscribed in 2004 as a segregate of the morphologically similar genus Melanelia.
Flavoparmelia is a genus of foliose lichens in the family Parmeliaceae. Because of their appearance, they are commonly known as greenshield lichens. The widely distributed genus contains 32 species. It was circumscribed by American lichenologist Mason Hale in 1986 to contain 17 former Pseudoparmelia species with broad lobes, usnic acid in the cortex, and isolichenan in the cell walls.
Parmelina is a genus of lichen belonging to the family Parmeliaceae. The genus was circumscribed in 1974 by American lichenologist Mason Hale with Parmelina tiliacea assigned as the type species.
Parmelinella is a genus of lichen belonging to the family Parmeliaceae. The genus was circumscribed in 1987 by John Elix and Mason Hale as a segregate of Parmelina, from which it differs in having larger ascospores and containing salazinic acid. Although the genus had been assumed to be well-defined morphologically, a 2021 molecular phylogenetic study suggests that the generic delimitations need to be revised.
Punctelia is a genus of foliose lichens belonging to the large family Parmeliaceae. The genus, which contains about 50 species, was segregated from genus Parmelia in 1982. Characteristics that define Punctelia include the presence of hook-like to thread-like conidia, simple rhizines, and point-like pseudocyphellae. It is this last feature that is alluded to in the vernacular names speckled shield lichens or speckleback lichens.
Relicina is a genus of foliose lichens belonging to the large family Parmeliaceae. It contains 59 species. Relicina was originally conceived as a series of the large genus Parmelia by lichenologists Mason Hale and Syo Kurokawa in 1964. A decade later, they promoted it to the status of genus.
Xanthoparmelia is a genus of foliose lichen in the family Parmeliaceae. Xanthoparmelia is synonymous with Almbornia, Neofuscelia, Chondropsis, Namakwa, Paraparmelia, and Xanthomaculina. This genus of lichen is commonly found in the United States, as well as Australia, New Zealand and Ecuador.
Psiloparmelia is a genus of lichen belonging to the family Parmeliaceae. It contains 13 Southern Hemisphere species, most of which are found growing on rocks at high elevations in South America. There are several characteristic features of the genus that are used to distinguish it from the morphologically similar genera, such as Arctoparmelia, Flavoparmelia, and Xanthoparmelia. These include a dark, velvety lower thallus surface that usually lacks rhizines, a negative test for lichenan, and a high concentration of usnic acid and atranorin in the cortex.
Xanthoparmelia pokornyi is a lichen species in the family Parmeliaceae. It contains the depsides gyrophoric acid and stenosporic acid.
Parmotrema albinatum is a species of foliose lichen in the family Parmeliaceae that is found in Hawaii. It was originally described in 2001 as Rimelia albinata. Later phylogenetic analysis demonstrated that the genus Rimelia was synonymous with Parmotrema, so this species was transferred to that genus. The lichen is characterized by the sorediate and short-lacinulate thallus with salazinic acid in the medulla and traces of lobaric acid. The upper surface of the thallus is whitish, which probably a result of the thickness of the thick upper cortex.
Remototrachyna is a genus of foliose lichens in the large family Parmeliaceae. It was separated from the genus Hypotrachyna based on the structure of the excipulum and genetic differences.
Emodomelanelia is a lichen genus in the family Parmeliaceae. It is monotypic, containing the single foliose Himalayan species Emodomelanelia masonii.
Xanthoparmelia loxodes is a species of foliose lichen in the family Parmeliaceae. It was first formally described by Finnish botanist William Nylander in 1872, as Parmelia loxodes. In 1978, Ted Esslinger created the genus Neofuscelia, which contained species previously classified in Parmelia subgenus Neofusca; Neofuscelia loxodes was one of many species transferred here. In a 2004 molecular phylogenetic study published by Oscar Blanco, Ana Crespo, John A. Elix, David L. Hawksworth and H. Thorsten Lumbsch, they showed that Neofuscelia did not form a clade distinct from Xanthoparmelia, and they reduced it to synonymy under Xanthoparmelia.
Salazinic acid is a depsidone with a lactone ring. It is found in some lichens, and is especially prevalent in Parmotrema and Bulbothrix, where its presence or absence is often used to help classify species in those genera.
Parmelina quercina is a species of foliose lichen in the large family Parmeliaceae. It is found in continental Europe.
