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.[1]
Placidium nigrum | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Eurotiomycetes |
Order: | Verrucariales |
Family: | Verrucariaceae |
Genus: | Placidium |
Species: | P. nigrum
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Binomial name | |
Placidium nigrum T.T.Zhang & X.L.Wei (2022)
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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 3,515 m (11,532 ft); it has since been collected at altitude ranges between 438 and 3,515 m (1,437 and 11,532 ft). 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.[1]
References
edit- ^ a b Zhang, Tingting; Zhang, Xin; Yang, Qiuxia; Wei, Xinli (2022). "Hidden species diversity was explored in two genera of catapyrenioid lichens (Verrucariaceae, Ascomycota) from the deserts of China". Journal of Fungi. 8: e729. doi:10.3390/jof8070729. PMC 9319096.