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.
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.
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 ahtiana is a species of foliose lichen in the family Parmeliaceae. It is known only from the type locality in Venezuela, where it was collected in the Guyana Shield at an elevation of 1,950 m (6,400 ft). It is named to honour Finnish lichenologist Teuvo Ahti.
Hypotrachyna alectorialiorum is a species of foliose lichen in the family Parmeliaceae. It is known only from the type locality in Minas Gerais, Brazil, where it was found growing on soil over rock, at an elevation of 1,200 m (3,900 ft). The specific epithet refers to the presence of the secondary chemicals alectorialic acid and hypoalectorialic acid.
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 aspera is a species of foliose lichen in the family Parmeliaceae. It occurs in the mountains of Minas Gerais and Paraná, where it grows on tree bark in humid forests at an elevation of about 1,100 m (3,600 ft).
Hypotrachyna boquetensis is a species of foliose lichen in the family Parmeliaceae. It was first described scientifically by lichenologist Mason Hale as a member of the genus Parmelia; he transferred it to the genus Hypotrachyna a year later. It is found in the mountains of Central and northern South America, where it grows on hardwood trunks and branches at elevations of 1,400–2,800 m (4,600–9,200 ft). It has also been recorded from India.
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 brevirhiza is a species of foliose lichen in the family Parmeliaceae. First described as a species of Parmelia by Syo Kurokawa in 1964, Mason Hale transferred it to the genus Hypotrachyna in 1975. The lichen is widespread in Central American Mountains and in the Andes at elevations of 2,700–4,300 m (8,900–14,100 ft), where it grows as an epiphyte on exposed trees and shrubs. It also occurs in southern South America, Africa, India, Indonesia, Papua New Guinea, Macquarie Island, and the Pacific.
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 appalachensis, commonly known as the Appalachian speckled shield lichen, is a species of foliose lichen in the family Parmeliaceae. It is found in the eastern United States and eastern Canada. The lichen was first formally described in 1962 by lichenologist William Culberson as a species of Parmelia. He collected the type specimen growing on tree bark in West Virginia, Hildur Krog transferred it to the newly circumscribed genus Punctelia in 1982.
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.
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.
