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Astrothelium aeneoides

From Wikipedia, the free encyclopedia

Astrothelium aeneoides
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Dothideomycetes
Order: Trypetheliales
Family: Trypetheliaceae
Genus: Astrothelium
Species:
A. aeneoides
Binomial name
Astrothelium aeneoides
Aptroot (2016)

Astrothelium aeneoides is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. It is found in Brazil, Guyana, and Puerto Rico, where it grows on the smooth bark of rainforest trees.

Taxonomy

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The lichen was formally described as a new species in 2016 by Dutch lichenologist André Aptroot. The type specimen was collected by the author in 1997 from the Parque Natural do Caraça in Serra do Caraça [pt] (Minas Gerais) at an altitude of 1,250 m (4,100 ft). The species epithet aeneoides alludes to its resemblance with Astrothelium aeneum.[1]

Description

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Astrothelium aeneoides has an olive-green to olive-grey, smooth and somewhat shiny thallus up to 8 cm (3.1 in) in diameter and about 0.2 mm thick. Its ascomata are immersed in the thallus; they are spherical, measuring 0.7–1.0  mm in diameter and arranged in groups of 2 to 5. They are contained in structures called pseudostromata (resembling a perithecium but containing both fungal tissue and substrate tissue) that have a raised surface texture distinct from that of the surrounding thallus. The ascospores, which number 8 per ascus, are hyaline, spindle-shaped (fusiform) with rounded ends, have 3 septa, and measure 20–25 by 6–9 μm. The internal chambers formed by the septa (the lumina) are diamond shaped. The use of thin-layer chromatography reveals the presence of a lichen product that the author suggests is parietin. The expected results of standard chemical spot tests are: thallus surface UV−, thallus medulla K−; pseudostroma surface UV+ (pink to orange), medulla of pseudostroma K+ (blood red).[1]

Astrothelium aeneum is similar in morphology; A. aenoides differs by a lack of orange pigment on the thallus. Another similar species, A. aenascens, is distinguished from A. aenoides by the presence of an inspersed hamathecium.[1] Astrothelium flavostromatum is another lookalike that is distinguished by a strongly convex and swollen (bullate) thallus and a cream-coloured pseudostromata.[2]

References

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  1. ^ a b c 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.
  2. ^ Aptroot, André; Cáceres, Marcela Eugenia da Silva (2016). "New Trypetheliaceae from the Amazon basin in Rondônia (Brazil), the centre of diversity of the genus Astrothelium". The Lichenologist. 48 (6): 693–712. doi:10.1017/s0024282915000584.