| Astrothelium megeustomum | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Dothideomycetes |
| Order: | Trypetheliales |
| Family: | Trypetheliaceae |
| Genus: | Astrothelium |
| Species: | A. megeustomum |
| Binomial name | |
| Astrothelium megeustomum Aptroot & C.A.V.Fraga (2016) | |
Astrothelium megeustomum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae, [1] first scientifically described in 2016. It is found in Brazil.
The species was formally described in 2016 by André Aptroot and Carlos Fraga. The type specimen was collected in Guaratuba, Paraná, Brazil. The second author found it growing on tree bark in arboreal restinga on 8 May 2015. [2]
Astrothelium megeustomum has a corticate , smooth, somewhat shiny, and continuous thallus covering areas up to 7 cm in diameter and about 0.2 mm thick. The thallus is pale yellowish-green and not surrounded by a prothallus . It does not induce gall formation on the host bark. Ascomata are pyriform (pear-shaped), measuring around 0.6–1.2 mm in diameter. They are mostly aggregated in groups of 2–5 and mostly immersed in the bark tissue below pseudostromata , which are distinctly raised above the thallus and mostly irregular in outline. The wall of the ascomata is carbonised and up to 80 μm thick. Ostioles are eccentric, fused, flat, pale brownish, white- pruinose , and surrounded by a whitish zone. Hamathecium does not contain oil globules. Asci contain eight ascospores each. Ascospores are hyaline, muriform , fusiform , measuring 117–125 by 17–21 μm, with pointed ends and surrounded by a gelatinous layer up to 10 μm thick. The median septum is thickened. Pycnidia were not observed. [2]
The thallus surface of Astrothelium megeustomum is UV negative, and the medulla has no reaction to the potassium hydroxide (K−) chemical spot test. The ostiolar region has a UV+ (yellow) reaction. Thin-layer chromatography analysis reveals the presence of lichexanthone, a xanthone substance that fluoresces when lit with a long-wavelength UV light. [2]
This species is found on smooth bark of trees in old-growth forest. At the time of its original publication, it was only known to occur in Brazil. [2]
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.
Astrothelium stromatofluorescens is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It is only known to occur in a few locations in Brazil and Bolivia.
Astrothelium mesoduplex is a species of lichen in the family Trypetheliaceae. It is similar to A. flavoduplex but has larger ascospores and lacks lichexanthone. This lichen species has been found only in Brazil, particularly in primary forests.
Astrothelium ochroleucoides is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It is found in Brazil and Guyana.
Astrothelium solitarium is a species of corticolous (bark-dwelling) in the family Trypetheliaceae. Found in Brazil, it was formally described as a new species in 2016 by lichenologists André Aptroot and Marcela Cáceres. The species is closely related to Astrothelium ceratinum but differs in its ascospore size.
Astrothelium supraclandestinum is a species of lichen in the family Trypetheliaceae. This lichen species is closely related to Astrothelium subclandestinum, but differs in its hamathecium, which is not inspersed. The species is widespread and has been observed in several countries across different continents.
Astrothelium testudineum is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It is found in Brazil.
Astrothelium xanthosuperbum is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It is found in Rondônia, Brazil. The species is characterized by its large muriform ascospores and is similar in appearance to Astrothelium disjunctum.
Viridothelium leptoseptatum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae, first described in 2016. Found in Brazil, it resembles Astrothelium aeneum but differs in several key aspects, including the absence of pigment on the thallus and specific features of its ascospores.
Trypethelium luteolucidum is a species of lichen in the family Trypetheliaceae, first formally described in 2016. Found in Brazil and Mexico, it is similar to Trypethelium regnellii, but differs by the presence of anthraquinone crystals in the pseudostromata.
Polymeridium longiflavens is a species of corticolous (bark-dwelling) crustose lichen in the family Trypetheliaceae, first described in 2016. It is found in Brazil.
Polymeridium endoflavens is a species of lichen in the family Trypetheliaceae, first described in 2016. This species is found in Brazil.
Astrothelium tetrasporum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae, first described in 2016. It is found in Brazil.
Astrothelium simplex is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae, first described in 2016. It is found in the Atlantic Forest of Brazil.
Astrothelium rubrocrystallinum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae, first described in 2016. It is found in Brazil.
Astrothelium macrostomum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. It is found in Brazil, Guyana, and Venezuela.
Astrothelium longisporum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. It occurs in the Atlantic Forest of Brazil.
Astrothelium graphicum is a species of lichen in the family Trypetheliaceae. This lichen features an extended, reticulate pseudostroma that is lower than its slightly bullate thallus.
Astrothelium globosum is a species of lichen in the family Trypetheliaceae. This species is characterised by its immersed ascomata and a thallus consisting of nearly spherical warts, along with distinctive 3-septate ascospores.
Astrothelium curvatum is a species of corticolous lichen in the family Trypetheliaceae. Found in Brazil, it was described as a new species in 2016. It is characterised by its immersed pyriform ascomata with lateral ostioles and bent, muriform ascospores.