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.
Irwin Murray Brodo is an emeritus scientist at the Canadian Museum of Nature, in Ottawa, Ontario, Canada. He is an authority on the identification and biology of lichens.
Flavoparmelia baltimorensis, the rock greenshield lichen, is a medium to large foliose lichen with a yellow green upper thallus surface when dry; its lobes are rounded without pseudocyphellae; and the upper surface is covered with globose, pustule-like growths resembling isidia. The lower surface is black with a narrow brown zone at the margins.
Pseudephebe is a genus of fruticose lichens in the family Parmeliaceae. It contains three species that grow on rocks.
Ahtiana is a fungal genus in the family Parmeliaceae. A monotypic genus, it contains the single species Ahtiana sphaerosporella, the mountain candlewax lichen, found in western North America. The species was originally classified as Parmelia sphaerosporella by Johannes Müller Argoviensis in 1891, before Trevor Goward established the new genus Ahtiana in 1985, naming it after Finnish lichenologist Teuvo Ahti. This foliose lichen is characterised by its pale yellowish-green thallus, spherical spores, laminal apothecia, and the presence of usnic and caperatic acids. It primarily grows on the bark of whitebark pine in subalpine and montane regions, though it occasionally colonises other conifers outside its preferred host's range.
Vulpicida is a genus of lichenized fungi in the family Parmeliaceae. Circumscribed in 1993 to contain species formerly placed in Cetraria, the genus is widespread in Arctic to northern temperate regions, and contains six species. The genus is characterized by the presence of the secondary metabolites pulvinic acid and vulpinic acid, compounds that when combined with usnic acid, give the species their characteristic yellow and green colors.
Nodobryoria is a genus of medium to large, reddish-brown lichens that are hair-like to shrubby in shape and grow on conifer trees. The genus contains three species, distributed in North America and Greenland, which were previously included in the genus Bryoria. Nodobryoria is similar in appearance to Bryoria, but is differentiated because it does not contain the polysaccharide lichenin, and it has a unique cortex composed of interlocking cells that look like pieces of a jigsaw puzzle when viewed under a light microscope.
Pseudocyphellae are structures in lichens that appear as tiny pores on the outer surface of the lichen. They are caused when there is a break in the cortex of the lichen, and the medullary hyphae extend to the surface. Pseudocyphellae are the same colour as the medulla of the lichen, which is generally white, but can be yellow in some species of Pseudocyphellaria and in Bryoria fremontii. The presence/absence, abundance, colour, and shape of pseudocyphellae can all be diagnostic features used to identify different species. They facilitate gas exchange through the surface of the lichen, and may provide an adaptive advantage in temperate environments.
Bryoria is a genus of lichenized fungi in the family Parmeliaceae. Many members of this genus are known as horsehair lichens. The genus has a widespread distribution, especially in boreal and cool temperate areas.
Alectoria is a genus of fruticose lichens belonging to the family Parmeliaceae.
Alectoria sarmentosa is a long-lived, perennial witch's-hair lichen. It is a light greenish colored and fruticose or bushy bodied. This epiphytic lichen belongs to the family Parmeliaceae and the suborder Lecanorineae, which includes six similar species. A. sarmentosa grows draped or strung over conifer tree limbs and deciduous shrub branches in Northern temperate rainforest. This lichen favors mature and old growth, wet conifer and hardwood forests with clean air. A. sarmentosa is sensitive to air pollution and used for air quality monitoring. Areas required by A. sarmentosa are found in northern and southern temperate zones and receive high rainfall. This lichen is commonly found in transitional areas between valley and mountainous forests, but usually avoiding the immediate coast.
Bryoria kockiana is a species of horsehair lichen in the family Parmeliaceae. It is found in North America, where it grows from the branches of conifer trees.
Gowardia zebrina is a rare species of fruticose lichen in the family Parmeliaceae. Found in Canada, it was formally described as a new species in 2020 by the lichenologists Trevor Goward and Leena Myllys. The type specimen was collected by Goward on Mount Cain at an altitude of 1,440 m (4,720 ft). Here the lichen was found growing on the lower branches of a hemlock tree. The specific epithet zebrina refers to the diagnostic alternating pale and dark banding pattern of the terminal branches. The lichen has a limited distribution, as it is only known to occur in coastal northwest North America, extending from the Insular Mountains of southern Vancouver Island north to Hazelton. Its preferred habitat is in open, wind-scoured old growth forests, and its preferred substrate is the trunks and lower branches of conifer trees like fir and hemlock.
Gowardia nigricans, commonly known as the gray hair lichen or gray witch's hair, is a species of fruticose lichen in the family Parmeliaceae.
Gowardia arctica is a species of terricolous (ground-dwelling), fruticose (bushy) lichen in the family Parmeliaceae. Found in arctic regions of Northern Canada and Russia, it was formally described as a new species in 2009 by Pekka Halonen, Leena Myllys, Saara Velmala, and Heini Hyvärinen. The type specimen was collected from Banks Island in Swan Lake ; here, at an elevation of 100 m (330 ft), it was found growing among mesic mountain heath. It also occurs along the Arctic Ocean coast of Russia. The lichen is richly branched, black to black-brown in colour, and reaches up to 13 cm (5.1 in) in diameter. It contains alectorialic acid and two other unknown lichen products.
Sulcaria spiralifera is a species of fruticose lichen in the family Parmeliaceae. First described in 1977 as a species of Bryoria, it was transferred to the genus Sulcaria in 2014 based on DNA analysis. The species comprises two chemical variants now recognized as varieties: the typical variety and var. pseudocapillaris, which differ in their chemical composition and spot test reactions. It is found in the northwestern United States, where it grows as an epiphyte, hanging from a variety of tree species in open or shaded maritime forests. The lichen is characterized by its pendulous brown thallus with spiral-arranged white pores (pseudocyphellae) on its surface, extending 4–12 cm in length.
Alectoria imshaugii, commonly known as spiny witches hair, is a species of fruticose lichen in the family Parmeliaceae that occurs in North America. It was described as a new species by the lichenologists Irwin Brodo and David L. Hawksworth in their 1977 monograph on the genus Alectoria. The species epithet honors Henry Andrew Imshaug. The variety venezuelensis, proposed in 1994, occurs in Venezuela.
Brodoa oroarctica, commonly known as the Arctic sausage lichen, mountain sausage lichen, or rockgrub, is a species of rock-dwelling, foliose lichen in the family Parmeliaceae. First described in 1974 by the Norwegian botanist Hildur Krog, it is characterised by its dark grey, irregularly spreading thallus with narrow cylindrical lobes that grow loosely attached to rock surfaces. The species has a primarily circumpolar distribution across Arctic regions of the Northern Hemisphere, extending southward along the Rocky Mountains in North America, with notable disjunct populations in the White Mountains of New Hampshire, the Adirondack Mountains of New York, and the island of Newfoundland. It is distinguished from related species by its chemical composition, containing atranorin and physodic acid, and its preference for exposed Arctic–alpine habitats with limited snow cover. While common in its main Arctic range, its isolated southern populations are of conservation interest due to their rarity and potential vulnerability to climate change.
Cladocetraria is a fungal genus in the family Parmeliaceae. It contains the single species Cladocetraria minuscula, a fruticose (shrubby) lichen. The genus was established in 2023 based on morphological and molecular studies that distinguished it from related genera. It is characterised by its small size, growing only 2–3 centimetres tall, with distinctive hollow, tube-like structures that branch in a fork-like pattern and have inward-curling tips covered in a white powdery coating. The lichen produces several chemical compounds, including usnic acid, which gives it its yellowish-green colour.
