Biology:Astrothelium curvatum

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Short description: Species of lichen

Astrothelium curvatum
Scientific classification edit
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Dothideomycetes
Order: Trypetheliales
Family: Trypetheliaceae
Genus: Astrothelium
Species:
A. curvatum
Binomial name
Astrothelium curvatum
Aptroot & M.Cáceres (2016)

Astrothelium curvatum is a species of corticolous lichen in the family Trypetheliaceae.[1] Found in Brazil, it was described as a new species in 2016. It is characterised by its immersed [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] ascomata with lateral ostioles and bent, [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] ascospores.[2]

Taxonomy

Astrothelium curvatum was formally described as a new species in 2016 by the lichenologists André Aptroot and Marcela Cáceres. The type specimen was collected in Sergipe, Brazil, at the Serra de Itabaiana National Park, on the southern slope at an elevation of approximately 400 m (1,300 ft). It was found by the authors on the bark of a tree in May 2014.[2]

Description

The thallus of Astrothelium curvatum is [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], smooth, and somewhat shiny. It is continuous, covering areas up to 3 cm (1.2 in) in diameter and less than 0.1 mm thick. The colour is olive-green, surrounded by a black [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], and it does not induce gall formation on the host bark. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] are [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], measuring 0.4–0.7 by 0.3–0.5 mm, and are single, immersed in the thallus, and mostly immersed in the bark. The wall around the ascomata is [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] and can be up to 100 μm thick. The ostioles are lateral, not fused, and can be flat or depressed, with a brown colour. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is interspersed with hyaline oil globules, and the asci contain 4–8 [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]. These ascospores are hyaline, [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], ellipsoid, usually bent, with rounded ends, measuring 74–90 by 25–34 μm. They do not have a distinctly thickened median septum and are not surrounded by a gelatinous layer.[2]

[[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] have not been observed in this species. In terms of chemistry, the thallus surface is UV-negative, and the thallus medulla is K-negative. Thin-layer chromatography, a technique used to identify chemical substances, revealed that no secondary substances (lichen products) are detectable.[2]

Astrothelium curvatum is notable for its immersed pyriform ascomata with lateral ostioles and the curved [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] ascospores. It is most closely related to Astrothelium puiggarii . The main difference between these species is that A. puiggarii typically has two ascospores in the ascus compared to the 4–8 found in A. curvatum.[2]

Habitat and distribution

Astrothelium curvatum is found on the smooth bark of trees in the Atlantic rainforest. At the time of its original publication, it was known to occur only in its type locality in Brazil.[2]

References

  1. "Astrothelium curvatum Aptroot & M. Cáceres". Species 2000: Naturalis, Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/J5DQ. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Aptroot, André; Mendonça, Cléverton de Oliveira; Andrade, Danyelly Santos; Silva, Jeanne dos Reis; Martins, Suzana Maria de Azevedo; Gumboski, Emerson; Fraga, Carlos Augusto Vidigal; Cáceres, Marcela Eugenia da Silva (2016). "New Trypetheliaceae from northern and southern Atlantic rainforests in Brazil". The Lichenologist 48 (6): 713–725. doi:10.1017/s0024282916000037. 

Wikidata ☰ Q95573597 entry