Peltula is a genus of small dark brown to olive or dark grey squamulose lichens. These lichens typically grow on rocks in arid and semi-arid environments worldwide. They consist of a fungus living in symbiosis with a photosynthetic partner, specifically a cyanobacterium of the genus Chroococcidiopsis. Peltula is the only genus in the family Peltulaceae, which belongs to the Lichinomycetes, a class of fungi that form lichens. The genus includes about 50 recognised species, which exhibit a variety of growth forms ranging from flat and crust-like to more complex, leaf-like structures. Peltula lichens play important ecological roles in harsh environments, contributing to soil stability and nutrient cycling.
Lecanora muralis(Protoparmeliopsis muralis) is a waxy looking, pale yellowish green crustose lichen that usually grows in rosettes radiating from a center (placodioid) filled with disc-like yellowish-tan fruiting bodies (apothecia). It grows all over the world. It is extremely variable in its characteristics as a single taxon, and may represent a complex of species. The fruiting body parts have rims of tissue similar to that of the main nonfruiting body (thallus), which is called being lecanorine. It is paler and greener than L. mellea, and more yellow than L. sierrae. In California, it may be the most common member of the Lecanora genus found growing on rocks (saxicolous).
Placidium nigrum is a species of squamulose (scaley), ground-dwelling lichen in the family Verrucariaceae. It is found in Northwest China and the Tibetan Plateau, where it grows on sandy soil surfaces in semi-arid and arid regions.
Pertusaria albineoides is a species of corticolous (bark-dwelling), crustose lichen in the family Pertusariaceae. Found on the Galápagos Islands, it was formally described as a new species in 2015 by Frank Bungartz, A.W.Archer, Alba Yánez-Ayabaca, and John Elix. The type specimen was collected on Alcedo Volcano at an altitude of 1,089 m (3,573 ft), where it was found growing on a partially shaded, rain- and wind-exposed trunk of Scalesia microcephala. The species epithet refers to the similarity to the species Pertusaria albinea, from which it differs by having thin-walled ellipsoid-shaped ascospores that are longer and narrower.
Placolecis kunmingensis is a species of saxicolous (rock-dwelling), crustose lichen in the family Catillariaceae. It is found in Yunnan, China. The lichen is characterised by a thallus that is areolate to squamulose in its centre, forming irregular patches or clumps 10–50 mm wide, as well as its ellipsoid or spherical ascospores with slightly thickened wall.
Flavoplaca oasis is a species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. It is widely distributed across Europe, and has been reported in Western Asia, China, and North Africa.
Filsoniana ferdinandmuelleri is a species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. It is found in Australia. The lichen has a squamulose (scaly) thallus, with a range of bright yellow to greenish-yellow and brownish-orange colours in its soredia and apothecia, respectively. The areoles of this lichen are varied in size, slightly raised from the thallus surface, and each carries one to four apothecia. The soralia are rounded or irregularly shaped, covering most of the thallus surface as a yellow to greenish-yellow mass. The apothecia have dark brownish-orange discs, surrounded by slightly paler yellow margins, with the spore-bearing asci containing typically eight brownish-golden ascospores.
Caloplaca himalayana is a species of lignicolous (wood-dwelling) crustose lichen belonging to the family Teloschistaceae. Found in the Himalayas of India, it was described as new to science in 2009. The lichen has a yellowish thallus with rusty red apothecial discs.
Sucioplaca is a single-species fungal genus in the family Teloschistaceae. It contains Sucioplaca diplacia, a saxicolous (rock-dwelling) crustose lichen. It is common and widely distributed in the Caribbean, Central America, and the Galápagos Islands, where it grows on coastal rocks.
Romjularia is a fungal genus in the family Lecideaceae, containing the single species Romjularia lurida, a saxicolous and terricolous squamulose lichen.
Siphulastrum is a genus of lichen-forming fungi in the family Pannariaceae. It has five species. The genus was circumscribed by Johannes Müller Argoviensis in 1889, with S. triste assigned as the type species.
Boreoplaca is a fungal genus in the family Ophioparmaceae. It comprises the single species Boreoplaca ultrafrigida, a saxicolous (rock-dwelling), squamulose lichen. Both the genus and species were described in 1994 by the Norwegian lichenologist Einar Timdal. The lichen is found in Eastern Siberia, the Russian Far East as well as in adjacent territories of north-east China, and in South Korea. The main characteristics of the lichen are its squamulose thallus, black lecideine apothecia, and Fuscidea-type asci.
Pseudopeltula is a genus of lichen-forming fungi in the family Gloeoheppiaceae. Established in 1995 by the lichenologist Aino Henssen, the genus currently includes four recognised species. These small cyanolichens are characterised by their squamulose (scaly) to peltate (shield-shaped) thalli, which lack a lower cortex and are attached to the substrate by rhizines. A key feature of Pseudopeltula is its complex apothecia, which have hymenia that often become divided by sterile tissue as they mature. The genus is primarily found in arid and semi-arid regions of North America, Mexico, and the Caribbean, where species typically grow on soil, rock, or thin soil over rock, often forming part of biological soil crusts in desert environments.
Parallopsora is a small genus of lichen-forming fungi in the family Ramalinaceae. Established in 2018, the genus contains three species that were previously classified under a related genus, Phyllopsora. These lichens form small, scale-like growths that overlap like roof tiles and typically appear pale green to bluish-green in colour. They reproduce through both small brown fruiting bodies and sometimes through powdery structures on their surface. The species are known to grow in tropical rainforests, particularly in Brazil, Peru and Cuba.
Roccellinastrum flavescens is a rare species of fruticose lichen in the family Pilocarpaceae. It is found only in the Walls of Jerusalem National Park in Tasmania, Australia. This pale yellow, shrub-like lichen grows exclusively on the twigs of pencil pine, a rare Tasmanian conifer. Described by Australian scientist Gintaras Kantvilas in 1990, it can be distinguished from related lichens by its unique chemistry, including traces of usnic acid, and its cottony texture that forms patches up to 1 centimetre across. The species is threatened by the vulnerability of its host tree to bushfire and was listed as endangered under Tasmanian law in 2005.
Peltula lobulata is a species of saxicolous (rock-dwelling), squamulose lichen that belongs to the family Peltulaceae. This species was first described in 2019 following its discovery in Beijing, China.
Peltula polyphylla is a ground-dwelling, squamulose lichen species in the family Peltulaceae, characterised by its distinctive multi-lobed structure. Found in China, it was described as a new species in 2022.
Peltula pseudoboletiformis is a species of saxicolous (rock-dwelling), squamulose lichen lichen in the family Peltulaceae, described in 2022. It is noted for its resemblance in thallus structure to the mushroom-forming fungal genus Boletus, which is reflected in its name.
Peltula submarginata is a species of saxicolous (rock-dwelling), squamulose lichen in the family Peltulaceae, first described in 2022. It occurs in China.
Usnocetraria oakesiana, commonly known as the yellow ribbon lichen, or the yellow-green ribbon lichen, is a species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. It occurs in Asia, Europe, the north-eastern United States, and eastern Canada.
