A lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. Lichens are important actors in nutrient cycling and act as producers which many higher trophic feeders feed on, such as reindeer, gastropods, nematodes, mites, and springtails. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not plants. They may have tiny, leafless branches (fruticose); flat leaf-like structures (foliose); grow crust-like, adhering tightly to a surface (substrate) like a thick coat of paint (crustose); have a powder-like appearance (leprose); or other growth forms.
A curved mirror is a mirror with a curved reflecting surface. The surface may be either convex or concave. Most curved mirrors have surfaces that are shaped like part of a sphere, but other shapes are sometimes used in optical devices. The most common non-spherical type are parabolic reflectors, found in optical devices such as reflecting telescopes that need to image distant objects, since spherical mirror systems, like spherical lenses, suffer from spherical aberration. Distorting mirrors are used for entertainment. They have convex and concave regions that produce deliberately distorted images. They also provide highly magnified or highly diminished (smaller) images when the object is placed at certain distances.
A fruticose lichen is a form of lichen fungi that is characterized by a coral-like shrubby or bushy growth structure. It is formed from a symbiotic relationship of a photobiont such as green algae or less commonly cyanobacteria and one, two or more mycobionts. Fruticose lichens are not a monophyletic and holophyletic lineage, but is a form encountered in many classes. Fruticose lichens have a complex vegetation structure, and are characterized by an ascending, bushy or pendulous appearance. As with other lichens, many fruticose lichens can endure high degrees of desiccation. They grow slowly and often occur in habitats such as on tree barks, on rock surfaces and on soils in the Arctic and mountain regions.
Acarospora socialis is a usually bright yellow areolate to squamulose crustose lichen in the family Acarosporaceae that grows up to 10 cm wide, mostly on rock in western North America. It is among the most common lichens in the deserts of Arizona and southern California. It grows on sandstone, intrusive and extrusive igneous rock such as granitics, in all kinds of exposures to sunlight, including vertical rock walls. It is found in North America, including areas of the Mojave Desert and Sonoran Desert region, to Baja California Sur. It is the most common yellow member of its genus in southwestern North America. It sometimes, but rarely, grows on other soil crusts. It is a pioneer species.
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).
Circinaria arida is a 0.5–6 cm, light olive-brown custose lichen that grows on rock, often like a cluster of little light brown to olive balls growing on pebbles, in the southwestern deserts of North America. It is also found in Eurasia, and arid parts of North America from the southern Great Plains and Midwest to California. It is warty (verrucose) with the warts sometimes cracking apart areolate. The warts or areolas have angular to rounded sides. The 0.2-2.3 mm, convex to flat-topped areolas are separated by deep fissures that may be as deep (0.1–2 mm) as the areaola is wide, so the lichen often appears to be made of clusters of little balls crammed up next to each other, although the areolas are sometimes isolated. In California it is commonly found growing on pebbles. Each areola has a single sunken black, dust covered (pruinose) fruiting body (apothecium) with a white rim. A thin strip of prothallus sometimes is at the outer edge, forming a narrow dark zone (fimbriate). The similar Aspicilia desertorum has a white pruina on the apothecia. It is negative for lichen spot tests, I−, K−, P−, C−.
Heppia is a genus of olive, brownish, gray, or blackish squamulose, crustose, or peltate like lichens. Heppia was once the type genus of the family Heppiaceae, but that family was folded into synonymy with Lichinaceae.
Acarospora elevata, the mountain cobblestone lichen, is a shiny dark reddish brown to dark brown verrucose to aereolate crustose lichen that grows up to 3 cm (1.2 in) wide on granite in central and southern California to Baja California, and high elevations in the Rocky Mountains. It is usually only found above 1,400 metres (4,600 ft) because it is eaten by red mites at lower elevations. In the Californias, it is mostly found at high elevations, but sometimes in coastal locations where it is less glossy. It grows in full sun, mostly on hard granite, but sometimes other igneous or carbonate rock, from 500 to 3,350 metres in elevation. It may start by growing on members of the genus Aspicilia, or other such pioneer species on hard rocks.
Acarospora schleicheri, the soil paint lichen, is a bleached to bright yellow areolate to squamulose lichen that commonly grows to 10 cm (4 in) on soil (terricolous) in arid habitats of southern California and Baja California, also in Europe and Africa. It produces rhizocarpic acid as a secondary metabolite, which gives it a yellow coloration and serves to protect it from the sun. Its lower surface is also yellow. It can be greenish when moist. Roundish, angular, or irregularly shaped squamules are 0.5–4 mm in diameter. There are 0–1 apothecia embedded in the thallus, with 0.4–1.2 mm roundish black to reddish-brown, or dark brown discs, which sometimes fill the areola so as to be lecanorine. It divides vegetatively on the soil. Asci are club shaped (clavate) and have 100 or more spherical to ellipsoid spores. Lichen spot tests are negative, and it is UV+ orange under ultraviolet light.
Acarospora thelococcoides is a pruinose verruculose (warty) crustose lichen that grows in patches up to 10 cm across that grows on soil (terricolous), especially soils made from decomposed granite. It grows from San Benito, California to Baja California, and inland to 930 metres (3,050 ft). Each roundish areole becomes more pruinose toward the top with has a single round apothecium that is immersed with a dark brown disc, so as to appear like a collection of white rings. This appearance gives it the common name, soil eyes lichen.
Peltigera lepidophora, commonly known as the scaly pelt, is a species of foliose lichen in the family Peltigeraceae. It was first described by Finnish lichenologist Edvard August Vainio in 1878 as a variety of Peltigera canina. German botanist Friedrich August Georg Bitter promoted it to species status in 1904.
Teuvoa is a genus of lichen-forming fungi in the family Megasporaceae. It was first classified by lichenologists Mohammad Sohrabi and Steven Leavitt in 2013, with Teuvoa uxoris asigned as the type species. This genus was delineated from the larger genus, Aspicilia, following a molecular phylogenetic analysis which revealed that the Aspicilia uxoris species group constituted a distinct lineage in the Megasporaceae. Initially containing three species, two additional species native to China were added in 2018. Teuvoa is characterised by its small ascospores and conidia, and the absence of secondary metabolites.
Punctelia subpraesignis is a species of foliose lichen in the family Parmeliaceae. It occurs in Mexico, South America, and East Africa, where it grows on bark and on rocks. Major characteristics of the lichen that distinguish it from other Punctelia species include the C+ and KC+ rose spot tests of the medulla, ascospores that are smaller than 20 μm, and unciform (hooklike) conidia.
Lathagrium is a genus of lichen-forming fungi in the family Collemataceae. It has 10 species of gelatinous lichens. Species in this genus typically grow on calcareous rocks, often amidst mosses, but can also be found on siliceous or serpentine rocks, mortar, or soil.
Psora taurensis is a species of terricolous (ground-dwelling), squamulose lichen in the family Lecanoraceae. It is found in the Taurus Mountains of Turkey.
Solorina crocea, commonly known as the orange chocolate chip lichen, is a species of terricolous (ground-dwelling) and foliose (leafy) lichen in the family Peltigeraceae. The lichen, which was first formally described by Carl Linnaeus in 1753, has an arctic–alpine and circumpolar distribution and occurs in Asia, Europe, North America, and New Zealand. It generally grows on the bare ground in sandy soils, often in moist soil near snow patches or seepage areas. Although several forms and varieties of the lichen have been proposed in its history, these are not considered to have any independent taxonomic significance.
Leptogium acadiense is a species of corticolous (bark-dwelling), foliose lichen in the family Collemataceae. Found in northeastern North America, it was formally described as a new species in 2016 by James Hinds, Frances Anderson, and James Lendemer. The species epithet refers to the Acadian region of eastern North America, where the lichen seems to be most common.
Astrothelium xanthosuperbum is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It is found in Rondônia, Brazil. The species is characterized by its large muriform ascospores and is similar in appearance to Astrothelium disjunctum.
Heppia arenacea is a species of terricolous (ground-dwelling) lichen in the family Lichinaceae. Discovered in Yemen, it is characterized by its sand-coloured thallus and the incorporation of soil particles throughout its vegetative parts. The lichen is found in soil crust communities over limestone and basaltic rock in desert habitats, as well as in partially sheltered areas between large boulders.
