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.
Hypotrachyna vainioi is a species of foliose lichen in the family Parmeliaceae. It is found in Brazil.
Hypotrachyna is a species of foliose lichen in the family Parmeliaceae. Originally described from specimens collected in Venezuela, it is found in mountains throughout the Neotropics, where it grows on pine and hardwood bark.
Hypotrachyna andensis is a species of foliose lichen in the family Parmeliaceae. It is known to occur in the Neotropics and in Papua New Guinea.
Hypotrachyna bogotensis is a species of foliose lichen in the family Parmeliaceae. It was first described scientifically by Finnish lichenologist Edvard August Vainio. Mason Hale transferred it to the genus Hypotrachyna in 1975. It is a common species in the high mountains of the Central America and the northern Andes. It has also been recorded from southern Chile and from Gough Island.
Hypotrachyna brasiliana is a species of foliose lichen in the family Parmeliaceae. It was originall described by William Nylander in 1885 as a species of Parmelia. Mason Hale transferred it to the new genus Hypotrachyna in 1975. The lichen is found in the mountains of southeastern Brazil at elevations of 800–2,400 m (2,600–7,900 ft), where it grows on siliceous rocks, or on mosses over rocks.
Hypotrachyna brevidactylata is a species of foliose lichen in the family Parmeliaceae. It is an uncommon species that occurs in the mountains of Costa Rica, and in the Andes of Bolivia and Ecuador, at elevations of 2,500–3,600 m (8,200–11,800 ft). Its specific epithet refers to its resemblance to Hypotrachyna brevispora, and the presence of laminal dactyls.
Hypotrachyna brueggeri is a species of foliose lichen in the family Parmeliaceae. Described as a new species in 2002, it is known only from the type locality in southeastern Brazil, where it was collected at elevations of 1,000–1,400 m (3,300–4,600 ft).
Punctelia rudecta, commonly known as the rough speckled shield or the speckleback lichen, is a North American species of foliose lichen in the family Parmeliaceae. This species can be readily identified by the light color of the thallus underside, the relatively large lobes at the edges of the thallus, and the tiny white pores present on the top of the thallus that are characteristic of the genus Punctelia. The lichen is quite abundant and widespread in the eastern and southeastern United States, although it also occurs in Canada and northern Mexico, but is less common in these regions. The lichen usually grows on bark, and less commonly on shaded rocks. There are several lookalike Punctelia species; these can often be distinguished from P. rudecta by differences in distribution or in the nature of the reproductive structures present on the thallus.
Punctelia eganii is a species of foliose lichen in the family Parmeliaceae. It was described as a new species in 2011 by Brendan Hodkinson and James Lendemer. It is named in honor of Robert S. Egan, U.S. lichenologist and professor of biology, who collected the type specimen. The lichen is morphologically identical to Punctelia rudecta, differing only in the production of the secondary metabolite lichexanthone, which was previously unknown in the genus Punctelia. The presence of this compound allows the two species to be distinguished with the use of ultraviolet light, which causes the pseudocyphellae of P. eganii to fluoresce. The type specimen was found in a beech-Magnolia forest in Haines Island Park in Monroe County, Alabama.
Punctelia caseana is a species of foliose lichen in the family Parmeliaceae. Its range covers eastern North America, extending south to central and northern Mexico, where it grows on the bark of many species of hardwood and conifer trees.
Punctelia cedrosensis is a species of foliose lichen in the family Parmeliaceae. It is endemic to Mexico, where it grows on the bark of conifers.
Parmotrema gardneri is a species of foliose lichen in the family Parmeliaceae. It was first formally described in 1955 by Carroll William Dodge as Parmelia gardneri, from specimens collected in Brazil. Emmanuël Sérusiaux transferred it to the genus Parmotrema in 1984. In addition to South America, it is also found in Africa, Asia, and North America.
Cetrelia chicitae is a species of foliose lichen in the family Parmeliaceae. It is found in eastern Asia, North America, and Europe, where it grows on mossy rocks and tree trunks.
Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in many lichens, and it is important in the taxonomy of species in several genera, such as Pertusaria and Pyxine. More than a dozen lichen species have a variation of the word lichexanthone incorporated as part of their binomial name. The presence of lichexanthone in lichens causes them to fluoresce a greenish-yellow colour under long-wavelength UV light; this feature is used to help identify some species. Lichexanthone is also found in several plants, and some species of fungi that do not form lichens.
Hypotrachyna osseoalba, commonly known as the grainy loop lichen, is a species of foliose lichen in the family Parmeliaceae. It is widely distributed in subtropical and temperate areas of the world. Characteristic features of the lichen include the pustules in its cortex, the somewhat linear shape of the lobes comprising the thallus, and the branched rhizines.
Hypotrachyna appalachensis is a species of blue-gray to gray foliose lichen in the family Parmeliaceae. It can be found growing in eastern North America in the southern Appalachian Mountains. The species grows on the bark or wood of trees, specifically hardwood trees, either on the tree's trunk or base. Its name was chosen due to its distribution being entirely restricted to the Appalachian Mountains. The species was originally thought to be Hypotrachyna minarum, which it is morphologically identical to, until molecular data showed H. appalachensis consistently produced higher concentrations of 4,5-di-O-methylhiascic acid. As a result, H. appalachensis can only be distinguished with certainty from H. minarum by using TLC, which can detect this molecular difference.
Hypotrachyna mcmulliniana is a species of foliose lichen in the family Parmeliaceae. It has a blue-grey thallus about 3-10 cm wide, with lobes 1.0–4.0 mm wide, and isdia without hairs.
Hypotrachyna kauffmaniana is a species of blue-gray to gray foliose lichen in the family Parmeliaceae. This species can only be located in eastern North America along the Appalachian Mountains, commonly found in Georgia, South Carolina, North Carolina, and Tennessee. The habitat of H. kauffmaniana is typically mid-elevation forests on both hardwood and conifer tree branches/trunks within the southern Appalachians. On rare occasions, this species can be found growing on non-calcareous rocks. H. kauffmaniana gathered its name in honor of Gary Kauffman, a botanist for the National Forest Service. H. kauffmaniana can be commonly confused alongside Hypotrachyna showmanii, but is distinguishable due to the former producing different levels of gyrophoric acid as well as possessing slightly different morphological properties.
