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.
Physcia stellaris is a species of lichen. It is pale grey, but darker in the centre, and lacks isidia, lobules, soredia and pruina.It tests positive K+ yellow upper cortex with a 10% potassium hydroxide solution. In North America, it is known colloquially as the fringed rosette lichen.
Parmelia sulcata is a foliose lichen in the family Parmeliaceae. It is very tolerant of pollution and has a cosmopolitan distribution, making it one of the most common lichens. It harbours a unicellular Trebouxia green algal symbiont.
Physcia is a genus of lichen-forming fungi in the family Physciaceae. The widely distributed genus contains about 80 species. The genus is cosmopolitan, and has been extensively studied in various regions in the past several decades, with significant biodiversity in South America identified as a central diversity hotspot. Physcia species are foliose, lobate lichens that grow with a loose to close appressed habit. Their upper surface is typically whitish, pale greenish, green-grey, or dark grey in colour. The thallus colour remains relatively unchanged when moistened. Physcia lichens typically grow on bark, on wood, or rock, although they have occasionally been recorded dwelling on man-made structures. They thrive in nutrient-rich environments and are expanding rapidly in urban areas of the United Kingdom previously affected by SO2 pollution.
Hypogymnia is a genus of foliose lichens in the family Parmeliaceae. They are commonly known as tube lichens, bone lichens, or pillow lichens. Most species lack rhizines that are otherwise common in members of the Parmeliaceae, and have swollen lobes that are usually hollow. Other common characteristics are relatively small spores and the presence of physodic acid and related lichen products. The lichens usually grow on the bark and wood of coniferous trees.
Xanthoparmelia conspersa, commonly known as the peppered rock-shield, is a foliose lichen and the type species of genus Xanthoparmelia. It is widely distributed in temperate zones, and has been recorded from Japan, Europe, Africa, North America, and South America.
Xanthoparmelia mexicana, commonly known as the salted rock-shield, is a foliose lichen in the family Parmeliaceae. It grows in 4–10 cm diameter rosettes of gray-green to yellow-green lobes in arid climates all over the world.
Parmelia saxatilis, commonly known as the salted shield lichen or crottle, is a species of foliose lichen in the family Parmeliaceae. Several morphologically similar species, formerly lumped together, are now distinguished by their DNA.
Physcia caesia, known colloquially as blue-gray rosette lichen and powder-back lichen, is a species of foliose lichenized fungus. First described by Georg Franz Hoffmann in 1784, it is common across much of Europe, North America and New Zealand, and more patchily distributed in South America, Asia, Australia and Antarctica. There are 2 subspecies: P. c. caesia and P. c. ventosa, as well as a number of distinct forms and varieties. Molecular studies suggest that the species as currently defined may be polyphyletic. It is typically pale gray shading to darker gray in the center, and grows in a small rosette, usually some 2–3 cm (0.79–1.18 in) across at maturity. It only rarely has apothecia, instead reproducing most often vegetatively via soredia, which are piled in round blue-gray mounds across the thallus's upper surface. It grows most often on rock—principally calcareous, but also basaltic and siliceous—and also occurs on bone, bark and soil. It is nitrophilic and is particularly common on substrates where birds perch.
Arctoparmelia separata, commonly known as the rippled ring lichen, is a species of foliose, ring lichen in the family Parmeliaceae with a roughly circumpolar distribution.
Parmotrema rampoddense, commonly known as the long-whiskered ruffle lichen, is a species of foliose lichen in the family Parmeliaceae. It is widely distributed in tropical regions and grows on the bark of oak and palm trees.
Parmotrema arnoldii, commonly known as the powdered ruffle lichen, is a widely distributed species of lichen in the family Parmeliaceae. It has been recorded from Africa, Asia, Europe, Oceania, Macaronesia, and North and South America.
Xanthoparmelia lineola, commonly known as the tight rock-shield, is a foliose lichen species in the genus Xanthoparmelia. It is a common species with a temperate distribution. Found in North America and South Africa, it grows on rocks.
Melanohalea elegantula, commonly known as the elegant camouflage lichen, is a species of lichen in the family Parmeliaceae. It was first described by Alexander Zahlbruckner in 1894 as Parmelia aspidota var. elegantula. Hungarian lichenologist Ödön Szatala promoted it to full species status, as Parmelia elegantula, in 1930. Ted Esslinger transferred it to the genus Melanelia in 1978. Finally, it was assigned to the newly circumscribed genus Melanohalea in 2004.
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 hypoleucites, commonly known as the southwestern speckled shield lichen, is a species of foliose (leafy) lichen in the family Parmeliaceae. First formally described by Finnish botanist William Nylander as a species of Parmelia, it was transferred to the genus Punctelia in 1982. The lichen is found in Africa, North America, and South America, where it grows on the bark of both hardwood and coniferous trees. Its greenish-grey thallus is covered with tiny white pseudocyphellae – minute holes in the thallus surface that facilitate gas exchange. Some macroscopic features that help distinguish this species from other related members of the genus include the presence and the structure of the apothecia, the absence of asexual surface propagules, and the light brown color of the thallus undersurface. Chemically, the presence of lecanoric acid in the medulla and atranorin in the cortex help distinguish it from lookalikes.
Flavopunctelia flaventior is a species of foliose lichen in the family Parmeliaceae. It was first formally described as a new species by James Stirton in 1877 as Parmelia flaventior. In 1982, Hildur Krog transferred it to the subgenus Flavopunctelia of her newly circumscribed genus Punctelia, created to contain Parmelia species with punctate (point-like) pseudocyphellae. Mason Hale raised this subgenus to generic status a couple of years later, setting Flavopunctelia flaventior as the type species of the new genus. The lichen is commonly known as the speckled greenshield. Flavopunctelia flaventior occurs in Asia, Europe, East Africa, North America, and South America.
Punctelia graminicola is a species of foliose (leafy) lichen in the family Parmeliaceae. It grows on rocks, and, less frequently, on bark in North America, South America, and East Africa. It has a blue-grey thallus measuring up to about 15 cm (6 in), covered with tiny pores called pseudocyphellae. Sometimes the lichen forms small lobes that project out from the surface. Fruiting bodies are uncommon in this species; if present, they resemble small cups with a brown internal disc measuring 3–10 mm (0.1–0.4 in) in diameter. A lookalike species, Punctelia hypoleucites, is not readily distinguishable from Punctelia graminicola by appearance or habitat alone; these species can only be reliably differentiated by examining the length of their conidia.
Punctelia borreri is a species of foliose lichen in the family Parmeliaceae. It is a common and widely distributed species, occurring in tropical, subtropical, and temperate regions of Africa, Asia, Europe, North America, Oceania, and South America. The lichen typically grows on bark of deciduous trees, and less commonly on rock. Some European countries have reported increases in the geographic range or regional frequency of the lichen in recent decades, attributed alternatively to a reduction of atmospheric sulphur dioxide levels or an increase in temperatures resulting from climate change.
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.
