| Watsoniomyces | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lichinomycetes |
| Order: | Lichinales |
| Family: | Lichinaceae |
| Genus: | Watsoniomyces D.Hawksw., M.Powell & T.Sprib. (2021) |
| Species: | W. obsoletus |
| Binomial name | |
| Watsoniomyces obsoletus (Nyl.) D.Hawksw., M.Powell & T.Sprib. (2021) | |
| Synonyms [1] | |
| |
Watsoniomyces is a single-species fungal genus in the family Lichinaceae. It contains the saxicolous (rock-dwelling) crustose lichen Watsoniomyces obsoletus.
The genus was circumscribed in 2021 by David Hawksworth, Mark Powell, and Toby Spribille to contain the species formerly known as Lecidea lichenicola. Molecular phylogenetic analysis showed that the species belonged to the family Lichinaceae in the order Lichinomycetes. The original material of Lecidea lichenicola was examined and determined to actually be a different species, Trapelia glebulosa . Further research showed that the earliest available name for this lichen is Lecidea obsoleta (originally described by William Nylander in 1865 [2] ), and so a modern collection was used to neotypify the species. Watsoniomyces obsoletus grows on chalk pebbles, and is the first known member of the Lichinomycetes that has an endolithic thallus. [3]
Genus Watsoniomyces stands out from all other known genera in the order Lichinomycetes because it has a thallus (the main body of the lichen) that grows inside rock surfaces (endolithic), unlike others that typically have a crusty (crustose) or slightly scaly ( subsquamulose ) surface or even a shrub-like (fruticose) growth. [3]
The prodominant photobiont partner is a cyanobacterium belonging to Scytonema , but it has also been found partnered with algae that have orange-pigmented chloroplasts (perhaps Trentepohlia ), and also with clusters of green algal cells similar to Chlorella . [3]
Watsoniomyces obsoletus typically grows on chalk pebbles found in disturbed environments, such as near rabbit burrows or in areas where the ground has been scraped, revealing chalk fragments on the surface. This species particularly favours smaller pebbles, no larger than 10 cm. It forms part of a unique community of various verrucarioid species and has been classified in the Lecideetum watsoniae group, based on studies conducted in Hertfordshire, Norfolk, Surrey, and Sussex. [3]
This lichen is confirmed to exist only in southern and eastern England, with sightings in Bedfordshire, Buckinghamshire, Cambridgeshire, Hertfordshire, the Isle of Wight, Norfolk, Surrey, Sussex, and Yorkshire. Over the past 50 years, it has disappeared from several locations in southern England, likely due to a decrease in rabbit grazing which allowed for more scrub growth. Despite being categorised as "least concern" and "nationally scarce" in British lichen conservation evaluations, Watsoniomyces obsoletus is considered significant for conservation as it is potentially endemic to the UK. It is suspected that this species might also be found on the French side of the English Channel, although it has not yet been reported from France or any other region. [3]
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.
Lichinales is the sole order of ascomycete fungi in the class Lichinomycetes. It contains three families: Gloeoheppiaceae, Lichinaceae, and Peltulaceae. Most species are lichenized. Lichinales was proposed in 1986 by German lichenologists Aino Henssen and Burkhard Büdel. The class Lichinomycetes was created by Valérie Reeb, François Lutzoni and Claude Roux in 2004.
Gloeoheppiaceae is a family of ascomycete fungi in the order Lichinales. The family contains ten species distributed amongst three genera. Most species are lichenised with cyanobacteria. Species in this family are mostly found in desert areas. Modern molecular phylogenetics analysis casts doubt on the phylogenetic validity of the family, suggesting a more appropriate placement of its species in the family Lichinaceae.
The Lichinaceae are a family of ascomycete fungi. Most species are lichenized with cyanobacteria, and have a distribution largely in temperate regions.
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.
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.
Corticifraga is a genus of lichenicolous fungi in the family Gomphillaceae. The genus was circumscribed by David Leslie Hawksworth and Rolf Santesson in 1990, with Corticifraga peltigerae assigned as the type species.
Hydropunctaria is a genus of saxicolous (rock-dwelling), crustose lichens in the family Verrucariaceae. The genus includes both aquatic and amphibious species, with members that colonise either marine or freshwater habitats. The type species, Hydropunctaria maura, was formerly classified in the large genus Verrucaria. It is a widely distributed species common to littoral zones. Including the type species, five Hydropunctaria lichens are considered marine species: H. adriatica, H. amphibia, H. aractina, H. orae, and H. oceanica.
Schaereria is a genus of lichen-forming fungi. It is the sole genus in the family Schaereriaceae, which itself is the only family in the Schaereriales, an order in the subclass Ostropomycetidae of the class Lecanoromycetes. Most Schaereria species are crustose lichens that live on rocks. Schaereria was first proposed by Gustav Wilhelm Körber in 1855 and was later taken up by other lichenologists despite periods of disuse.
Toensbergia is a genus of lichen-forming fungi in the family Sporastatiaceae. The genus was circumscribed by Mika Bendiksby and Einar Timdal in 2013. The genus name honours Norwegian lichenologist Tor Tønsberg, "in appreciation of his important work on sorediate, corticolous lichens". The type species is Toensbergia leucococca, which was formerly classified in genus Hypocenomyce, presumably due to its resemblance to Hypocenomyce xanthococca.
Atrophysma is a fungal genus in the family Pannariaceae. It contains the single species Atrophysma cyanomelanos, a crustose lichen found only in Alaska.
Porpidia seakensis is a species of crustose lichen in the family Lecideaceae. It is an endolithic species, meaning it grows inside the rocks, between the grains. Found only in Alaska, it was formally described as a new species in 2020 by British lichenologist Alan Fryday. The type specimen was collected in the Hoonah-Angoon Census Area, in Glacier Bay National Park. Here it was discovered growing on granitic rock in a woodland. The lichen is only known from this area, although it is locally common. Its preferred habitat is siliceous rocks and boulders in wooded areas that are open and well lit. The specific epithet seakensis uses the letters "seak" to refer to a standard abbreviation for southeast Alaska.
Bacidina circumpulla is a species of crustose lichen in the family Ramalinaceae. Found in Alaska and British Columbia, it was described as a new species in 2020 by Stefan Ekman.
Fuscidea muskeg is a species of crustose lichen in the family Fuscideaceae. Found in Alaska, it was described as a new species in 2020 by Tor Tønsberg and Martina Zahradníková. The type species was collected in the Hoonah-Angoon Census Area of Glacier Bay National Park. Here it was found growing on a branch of the tree Pinus contorta in muskeg. The specific epithet muskeg is an Algonquin word for a blanket bog.
Lambiella aliphatica is a species of crustose lichen in the family Xylographaceae. Found in Alaska, it was described as a new species in 2020 by Toby Spribille and Philipp Resl. The type specimen was collected in the Hoonah-Angoon Census Area of Glacier Bay National Park. Here it was found at an altitude of 907 m (2,976 ft) growing on an argillite rock in alpine scree. The specific epithet aliphatica refers to the unidentified fatty acids that are present in the thallus. It is the first member of genus Lambiella to contain primarily fatty acids in the thallus. Lambiella globulosa is similar in morphology, but this species contains stictic acid rather than fatty acids as the primary secondary metabolite.
Sagiolechia phaeospora is a species of crustose lichen in the family Sagiolechiaceae. It is found in the alpine tundra of Alaska.
Toensbergia blastidiata is a species of crustose lichen in the family Sporastatiaceae. Found in northwestern North America, it was described as a new species in 2020 by lichenologists Toby Spribille and Tor Tønsberg. The type specimen was collected in Glacier Bay National Park at the base of Marble Mountain (Alaska). Here the lichen was found growing on the bark of Alnus viridis subsp. crispa. The specific epithet blastidiata refers to the "blastidiate thallus surface"; blastidia are vegetative propagules containing both mycobiont and photobiont, which are produced by yeast-like "budding".
Harpidiaceae is a small family of lichen-forming fungi, containing two genera and five species. It is of uncertain classification in the Pezizomycotina.
The following outline provides an overview of and topical guide to lichens.