Placidium is a genus of crustose to squamulose to almost foliose lichens. The genus is in the family Verrucariaceae.[1] Most members grow on soil (are terricolous), but some grow on rock (saxicolous).[2] 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.[2]
Members of the genus are commonly called stiplescale lichens or earthscale.[2]: 327
^Cite error: The named reference Wijayawardene et al. 2022 was invoked but never defined (see the help page).
^ abcField Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, ISBN 978-0-300-19500-2
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)...
Placidium arboreum, commonly known as the tree stipplescale, is a species of corticolous (bark-dwelling), squamulose (scaley) lichen in the family Verrucariaceae...
Placidium nigrum is a species of squamulose (scaley), ground-dwelling lichen in the family Verrucariaceae. It is found in Northwest China and the Tibetan...
described in 1857 by Italian lichenologist Abramo Bartolommeo Massalongo as Placidium compactum. After having been shuffled to various genera in its taxonomic...
phylogenetics to belong to genus Placidium, Cécile Gueidan and colleagues proposed to unite Clavascidium with Placidium in a 2009 publication. Despite this...
which means "scale"). Lichenomphalia hudsoniana Normandina pulchella Placidium arboreum In addition to the above forms, lichenologists have named a handful...
Catapyrenium, Heteroplacidium, Involucropyrenium, Neocatapyrenium, Placidiopsis, Placidium, and Scleropyrenium, and, as of 2010, numbered 81 species. The morphological...
Catapyrenium. Other morphologically similar genera are Neocatapyrenium, Placidium, and Scleropyrenium, although molecular phylogenetic analyses indicate...
of members of the genus are similar to members of Heppia, Psora, and Placidium, although the first genus has cyanobacteria from the genus Scytonema,...
Lecanora dispersa and Xanthomendoza fallax. (19 December 1983) L-174 Placidium lacneum (Ach.) Breuss [EGW] Collected and identified by EGW; on rock outcrop...
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