Stromatella bermudana is a saxicolous (rock-dwelling) crustose lichen. It is the only species in Stromatella, a monotypic fungal genus in the family Lichinaceae.
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.
Lichens are symbiotic organisms made up of multiple species: a fungus, one or more photobionts and sometimes a yeast. They are regularly grouped by their external appearance – a characteristic known as their growth form. This form, which is based on the appearance of vegetative part of the lichen, varies depending on the species and the environmental conditions it faces. Those who study lichens (lichenologists) have described a dozen of these forms: areolate, byssoid, calicioid, cladoniform, crustose, filamentous, foliose, fruticose, gelatinous, leprose, placoidioid and squamulose. Traditionally, crustose (flat), foliose (leafy) and fruticose (shrubby) are considered to be the three main forms. In addition to these more formalised, traditional growth types, there are a handful of informal types named for their resemblance to the lichens of specific genera. These include alectorioid, catapyrenioid, cetrarioid, hypogymnioid, parmelioid and usneoid.
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.
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.
Placolecis sublaevis is a species of saxicolous (rock-dwelling), crustose lichen in the family Catillariaceae. It is found in Yunnan and Sichuan, China. The crust-like, radiating body of the lichen forms irregular patches or clumps and includes numerous false conidiomata, a type of asexual reproductive structure, within its thallus. Its lobes, dark brown and slightly flattened at the top, form larger groups at the edges and contain an upper layer composed of loosely interwoven cells and a lower inner tissue that varies from reddish-orange to white.
Harusavskia is single-species fungal genus in the family Teloschistaceae. It contains the little-known species Harusavskia elenkinianoides, a saxicolous (rock-dwelling), crustose lichen. This species is known only from its original collection site near the Laguna del Maule in Chile.
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.
Awasthia is a monotypic fungal genus in the family Physciaceae. It contains the single species Awasthia melanotricha, a foliose lichen found in the Nepal Himalayas.
Pseudoheppia is a fungal genus in the family Lichinaceae. It contains a single species, Pseudoheppia schuleri, a saxicolous (rock-dwelling) squamulose lichen.
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.
Callome is a fungal genus in the family Collemataceae. It consists of the single species Callome multipartita, a saxicolous (rock-dwelling), crustose lichen found in Northern Africa, Europe, and North America.
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.
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 polycarpa is a species of saxicolous (rock-dwelling), squamulose lichen in the family Peltulaceae. First described in 2022, it is endemic to Beijing's Mentougou District in 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 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.
