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Placidium
''Placidium'' is a genus of crustose to squamulose to almost foliose lichens. The genus is in the family Verrucariaceae. Most members grow on soil (are terricolous), but some grow on rock ( saxicolous). The fruiting bodies are perithecia, flask-like structures immersed in the lichen body (thallus) with only the top opening visible, dotting the thallus. Lichen spot tests are all negative. Members of the genus lack rhizines, but otherwise resemble members of the genus ''Clavascidium''. Members of the genus are commonly called stiplescale lichens or earthscale.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, Taxonomy The genus was circumscribed in 1855 by Italian lichenologist Abramo Bartolommeo Massalongo. María Prieto and Ibai Olariaga suggest that ''Placidium'' is a superfluous illegitimate name according to strict application of nomenclatural rules. This is because when Massalongo circumscribed the genus in 1855, he included the original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placidium Varium
''Placidium'' is a genus of crustose to squamulose to almost foliose lichens. The genus is in the family Verrucariaceae. Most members grow on soil (are terricolous), but some grow on rock (saxicolous). The fruiting bodies are perithecia, flask-like structures immersed in the lichen body (thallus) with only the top opening visible, dotting the thallus. Lichen spot tests are all negative. Members of the genus lack rhizines, but otherwise resemble members of the genus ''Clavascidium''. Members of the genus are commonly called stiplescale lichens or earthscale.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, Taxonomy The genus was circumscribed in 1855 by Italian lichenologist Abramo Bartolommeo Massalongo. María Prieto and Ibai Olariaga suggest that ''Placidium'' is a superfluous illegitimate name according to strict application of nomenclatural rules. This is because when Massalongo circumscribed the genus in 1855, he included the original ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placidium Arboreum
''Placidium arboreum'', commonly known as the tree stipplescale, is a species of corticolous (bark-dwelling), squamulose (scaley) lichen in the family Verrucariaceae. It has a primarily North American distribution, with a range extending from eastern Canada south to Mexico, although it has also been reported from the West Indies and from Argentina. Taxonomy The lichen was first mentioned in the scientific literature as ''Endocarpon arboreum'' in an 1831 publication of Elias Fries, who attributed authorship to Lewis David de Schweinitz. Fries wrote of the lichen: "In addition there is a variety, ''Endocarpon arboreum'' of Schweinitz from North America, which by its description should be referred here but from its whole structure seems to be a poorly developed ''Sticta''". Fries does not seem to have accepted it as a valid species. Further, because no description or diagnosis of the taxon was provided (i.e., as a nomen nudum), the name was not validly published according to nome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verrucariaceae
The Verrucariaceae are a family of mostly lichenised fungi in the order Verrucariales. The lichen-forming species, which comprise the vast majority of the family, have a wide variety of thallus forms, and include crustose (crust-like), foliose (bushy), and squamulose (scaly) representatives. Several characteristics of the spore-bearing structures, the ascomata, define the family, including their perithecioid form–more or less spherical or flask-shaped, with a single opening and otherwise completely enclosed by a wall. Squamulose members of the Verrucariaceae with simple ascospores (lacking partitions called septa), and without algae in the spore-bearing region are known as lichens; there are more than 80 of these species. The family has several dozen lichenicolous (lichen-dwelling) examples, including a few genera that contain solely lichenicolous members. An unusually diverse variety of photobiont partners have been recorded, mostly green algae, but also brown algae and yel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placidium Nigrum
''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. The lichen was formally described as new to science in 2022 by Tingting Zhang and Xinli Wei. The type specimen was collected from the Da Qaidam (Haixi Mongol and Tibetan Autonomous Prefecture), at an altitude of ; it has since been collected at altitude ranges between . The species epithet ''nigrum'' alludes to the black area surrounding the thallus that results from an aggregation of pycnidia ( asexual fruiting bodies). These abundant, tiny pycnidia occur both superficially on the thallus surface (''laminal'') and on the lobe edges (''marginal''). ''Placidium nigrum'' does not react with any of the standard chemical spot tests, and no lichen products were detected from the species using thin-layer chromatography Thin-layer chromatography ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clavascidium
''Clavascidium'' is a genus of lichens in the family Verrucariaceae. The genus was circumscribed in 1996 by Austrian lichenologist Othmar Breuss. Because the type species of the genus, ''Clavascidium umbrinum'', has been shown using molecular phylogenetics to belong to genus ''Placidium'', Cécile Gueidan Cécile Gueidan is a mycologist and lichenologist who applies morphological and molecular biological methods to the origin and taxonomy of fungi that live in lichen symbioses and within rocks. Early life and education Gueidan began working o ... and colleagues proposed to unite ''Clavascidium'' with ''Placidium'' in a 2009 publication. Despite this, the genus has been retained in recent publications of fungal classification. Species *'' Clavascidium antillarum'' *'' Clavascidium imitans'' *'' Clavascidium kisovense'' *'' Clavascidium krylovianum'' *'' Clavascidium lacinulatum'' *'' Clavascidium pseudorufescens'' *'' Clavascidium semaforonense'' *'' Clavascidium s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
