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 characterised 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 metabolites. Melanohalea was circumscribed in 2004 as a segregate of the morphologically similar genus Melanelia, which was created in 1978 for certain brown Parmelia species. The methods used to estimate the evolutionary history of Melanohalea suggest that its diversification primarily occurred during the Miocene and Pliocene epochs.
Xanthoparmelia is a genus of foliose lichens in the family Parmeliaceae. This genus of lichen is commonly found in the United States, as well as Australia, New Zealand and Ecuador.
Xanthoparmelia mougeotii is a species of foliose lichen belonging to the family Parmeliaceae.
Hypotrachyna lueckingii is a species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. It is only known to occur at high elevations on the Cordillera de Talamanca in Costa Rica.
Relicina colombiana is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae. Found in high-elevation páramo of the Eastern Cordillera in Colombia, it was described as new to science in 2011.
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 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.
Bulbothrix meizospora is a species of foliose lichen in the family Parmeliaceae. It is found in Africa, Asia, and South America, where it grows on tree bark.
Xanthoparmelia serusiauxii is a species of foliose lichen in the family Parmeliaceae. Found in Namibia, it was formally described as a new species in 1986 by American lichenologist Mason Hale. The type specimen was collected by Hale from the Laguneberg Mountains, southeast of Cape Cross. There, it is common on dolerite boulders and small, flat pebbles. The specific epithet honours Emmanuël Sérusiaux, who, according to Hale, "was the first lichenologist to collect this unusual lichen in Namibia".
Xanthoparmelia isidiovagans is a species of foliose lichen in the family Parmeliaceae
Xanthoparmelia perezdepazii is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae. It is found in the Canary Islands.
Ramalina geniculatella is a species of saxicolous (rock-dwelling), fruticose lichen in the family Ramalinaceae. It is found in the remote tropical island of Saint Helena, where it grows on boulders and cliffs. It was formally described as a new species in 2008 by Dutch lichenologist André Aptroot. The type specimen was collected by the author from Prosperous Bay Plain at an elevation of 330 m (1,080 ft); there, it was found growing on basalt. The initially shrub-like, fruticose thallus of the lichen later becomes pendant, reaching lengths of up to 20 cm (8 in), although typically it is smaller, about 7 cm (2.8 in). The branches of the thallus are about 0.5–1.2 mm wide and about 0.2–0.5 mm thick; they are geniculate below the apothecia. The species epithet refers to this characteristic feature. Although the branches are greenish-grey, they are covered with whitish pseudocyphellae, which gives the thallus an overall whitish appearance. Thin-layer chromatography shows that the species contains usnic acid, and sometimes boninic acid and protocetraric acids. The photobiont partner is dispersed in irregular groups throughout the medulla.
Canoparmelia rarotongensis is a species of foliose lichen in the family Parmeliaceae. Found in Rarotonga, it was formally described as a new species in 2000 by Simone Louwhoff and John Elix. The type specimen was collected by the second author from the Muri Lagoon, where it was found growing on hibiscus along the foreshore. It is named for its type locality. The main physical characteristic that distinguishes it from others in its genus is its conspicuous isidia, which are consistently inflated and branched.
Parmotrema lawreyi is a species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. Found on the Galápagos Islands, it was formally described as a new species in 2019 by lichenologists Frank Bungartz and Adriano Spielmann. The type specimen was collected by the first author from the foothills of Media Luna on San Cristóbal Island, where it was found in dry, open woodland growing on the trunk of Bursera graveolens. The species epithet honours the authors' colleague James D. Lawrey, "on the occasion of his 70th birthday".
Parmotrema cactacearum is a rare species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. Found on the Galápagos Islands, it was formally described as a new species in 2019 by lichenologists Frank Bungartz and Adriano Spielmann. The type specimen was collected from Pinta Island at an altitude of 289 m (948 ft), where it was found growing on an old cactus pad in an open woodland. It is only known from the type specimen. The species epithet refers to its substrate.
Heterodermia fragmentata is a species of corticolous (bark-dwelling) foliose lichen in the family Physciaceae. It occurs in Sri Lanka.
Xanthoparmelia nomosa is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae. It is found in Tasmania, Australia.
Xanthoparmelia somervilleae is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae. It is found in Tasmania, Australia.
Hypotrachyna constictovexans is a little-known species of foliose lichen in the family Parmeliaceae. Known only from a single specimen collected in 1976, it is found in the highlands of Peru. Its thallus can grow over 5 cm wide, featuring long, straight, and separate lobes that are highly convex and tube-like, with a pale grey, slightly shiny upper surface adorned with cylindrical isidia.
Xanthoparmelia alligatensis is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae, described by John Elix in 2006. The species is native to South Australia, specifically found in the Mount Remarkable National Park.
