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.
The ecology of the Sierra Nevada, located in the U.S. states of California and Nevada, is diverse and complex. The combination of climate, topography, moisture, and soils influences the distribution of ecological communities across an elevation gradient from 500 to 14,500 feet. Biotic zones range from scrub and chaparral communities at lower elevations, to subalpine forests and alpine meadows at the higher elevations. Particular ecoregions that follow elevation contours are often described as a series of belts that follow the length of the Sierra Nevada. There are many hiking trails, paved and unpaved roads, and vast public lands in the Sierra Nevada for exploring the many different biomes and ecosystems.
Calvitimela is a lichen genus in the family Tephromelataceae. Members of the family Tephromelataceae are crustose lichens with green photobionts and lecideine or lecanorine apothecia. The species in Calvitimela have lecideine apothecia, are saxicolous and are primarily found in alpine to arctic regions.
Acarospora janae is a species of lichen in the Acarosporaceae family. Described as new to science in 2011, it is known only from New Mexico and Colorado in the United States, where it grows on siliceous rock.
Lepidostromatales is an order of fungi in the class Agaricomycetes. It is the only known order of basidiomycete fungi composed entirely of lichenized members. Morphologically, the fruiting bodies of all species are clavarioid. Six species are known, five of which were described within the span of 2007–2013. Due to its morphological similarity to the genus Multiclavula, its isolated phylogenetic position was not understood until quite recently. The photobionts that have been found in association with members of this group are not known to associate with any other types of lichenized fungi.
Lichens of the Sierra Nevada have been little studied. A lichen is a composite organism consisting of a fungus and a photosynthetic partner growing together in a symbiotic relationship.
Crustose lichens are lichens that form a crust which strongly adheres to the substrate, making separation from the substrate impossible without destruction. The basic structure of crustose lichens consists of a cortex layer, an algal layer, and a medulla. The upper cortex layer is differentiated and is usually pigmented. The algal layer lies beneath the cortex. The medulla fastens the lichen to the substrate and is made up of fungal hyphae. The surface of crustose lichens is characterized by branching cracks that periodically close in response to climatic variations such as alternate wetting and drying regimes.
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).
Acarospora fuscata is a glossy pale or yellowish-brown areolate lichen with angular areolas that grows up to 10 cm (4 in) wide on non-calcareous rock in low and high elevations. It grows in Europe and North America. It grows in southern California and on the eastern part of the Sierra Nevada range. It may grow with the areolas disconnected. The areolas may lift at the edges, but the areolas do not overlap like true squamules (sub-squamulose). More common in the Sierras is the similar species Acarospora thamnina, which is truly squamulose with overlapping scales.
Lecanora polytropa, commonly known as the granite-speck rim lichen, is a species of saxicolous lichen in the family Parmeliaceae. A small, inconspicuous species that grows in the cracks of rock surfaces, it has a cosmopolitan distribution and has been recorded on all continents, including Antarctica.
Acarospora pseudofuscata is a species of saxicolous (rock-dwelling) crustose lichen in the family Acarosporaceae. It occurs on a few islands in the Aegean Sea and in Turkey.
Lecanora lojkahugoi is a species of saxicolous (rock-dwelling) crustose lichen in the family Lecanoraceae. It is found in the Russian Far East and in South Korea.
Xanthoparmelia schmidtii is a lichen which belongs to the Xanthoparmelia genus. The lichen is uncommon and is listed as endangered by the Nature Conservatory.
Catillaria gilbertii is a rare species of saxicolous (rock-dwelling), crustose lichen in the family Catillariaceae. It is found in the Central Highlands of Scotland.
Lecidea tessellata is a species of saxicolous (rock-dwelling), crustose lichen in the family Lecideaceae. It was formally described as a species in 1819 by German botanist Heinrich Flörke. In northern North America, it is common and widely distributed, growing on non-calcareous rocks. It also occurs in Afghanistan, China, Nepal, Europe, and Russian Asia. In India, it has been recorded only from the alpine Western Himalayas at an altitude of 3,450 m (11,320 ft). Its southern distribution extends to James Ross Island, where it is locally common.
Lecidea hoganii is a rare species of saxicolous (rock-dwelling), crustose lichen in the family Lecideaceae. It is known to occur only in Boulder, Colorado, where it grows in association with other lichens in mixed saxicolous communities on sandstone in the Fox Hills Formation. The lichen is characterized by its thick white, chalky thallus, sessile to raised apothecia, presence of a dark pink pigment in the hymenium, and absence of secondary compounds.
Charcotiana is a single-species genus in the family Teloschistaceae. It contains the species Charcotiana antarctica, a crustose lichen found in Antarctica.
Lecidea lygommella is a species of saxicolous (rock-dwelling), crustose lichen in the family Lecideaceae. It spreads up to 7 cm wide with a thin thallus varying in colour from whitish and pale grey to rusty red-brown, featuring areolate surfaces with irregularly shaped areoles. Its fruiting bodies range from slightly embedded to sitting atop the thallus and black, flat to slightly convex apothecial discs. Unlike its lookalike Lecidea lygomma, L. lygommella does not produce any secondary chemicals. It is found in New South Wales and Victoria, Australia, where it grows on rocks in alpine areas.
Kuettlingeria soralifera is a saxicolous (rock-dwelling), crustose lichen species in the family Teloschistaceae, first described in 2006. It is similar to Kuettlingeria xerica but distinguished by the presence of soredia on its thallus.
