Astrothelium macroeustomum is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. Found in French Guiana, it was formally described as a new species in 2019 by lichenologists André Aptroot and Harrie Sipman. The type specimen was collected by Sipman from the Piste Crique Limonade at an altitude of 300 m (980 ft). The lichen has a mostly smooth, pale ochraceous-brown thallus that is somewhat shiny and covers areas up to 9 cm (4 in) in diameter. It is surrounded by a dark brown prothallus. It has pear-shaped (pyriform) ascomata, measuring 0.6–1.0 mm in diameter, which mostly aggregate in groups of two to five, and are more or less immersed in the tissue of the bark, below the thallus surface. They have convex, black ostioles (pores) that are surrounded by a yellowish-white ring of pruina. The ascospores are hyaline, spindle-shaped (fusiform) with five septa and measure 50–55 by 12–17 μm. The lichen contains lichexanthone, a lichen product that causes the ostioles of the ascomata to fluoresce yellow when lit with a long-wavelength UV light. The specific epithet macroeustomum refers to both its large spores and its similarity to Astrothelium eustomum.
Astrothelium quasimamillanum is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. Found in Brazil, it was formally described as a new species in 2019 by lichenologists André Aptroot and Cléverton de Oliveira Mendonça. The type specimen was collected by Mendonça from the Municipal nature park at an altitude of 100 m (330 ft). The lichen has a smooth and shiny, dark brown thallus that is surrounded by a dark brown prothallus and covers areas up to 7 cm (3 in) in diameter. It has pear-shaped (pyriform) ascomata, measuring 0.6–0.9 mm in diameter, which mostly occur either immersed in the bark, or as barely discernible black structures under the thallus cortex. The ascospores are hyaline, ellipsoid in shape, and muriform, with dimensions of 30–33 by 9.5–10.5 μm. The specific epithet quasimamillanum alludes to its slight similarities with members of the Pyrenula mamillana species group.
Astrothelium studerae is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. Found in Brazil, it was formally described as a new species in 2019 by lichenologists André Aptroot and Marcela Eugenia da Silva Cáceres. The type specimen was collected by the authors from the Pedra Talhada Biological Reserve at an altitude between 500 and 700 m. The specific epithet studerae honours Anita Studer, "the protector of the isolated patch of Atlantic rainforest in Alagoas where the new species was collected".
Astrothelium decemseptatum is a species of corticolous (bark-dwelling), crustose lichen 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 type specimen was collected by the authors in the Sítio Ecológico Buriti on Lago Cujubim, in a disturbed rainforest. The lichen has a smooth and somewhat shiny, pale yellowish-grey thallus that lacks a prothallus and covers areas of up to 7 cm (2.8 in) in diameter. The ascomata are pear-shaped (pyriform) and typically occur in aggregated groups of two to five, usually immersed in the bark tissue. The species epithet decemseptatum refers to the ascospores, which usually have between nine and eleven septa that divide the spore into distinct compartments. Anthraquinone compounds were detected in collected samples of the lichen using thin-layer chromatography. The characteristics that distinguish it from other members of Astrothelium include its ascomata, which are solitary to irregularly confluent, immersed in large thallus verrucae, and have scattered, external, pink pigment, and an inspersedhamathecium; and the dimensions of the ascospores.
Astrothelium eumultiseptatum is a species of corticolous (bark-dwelling), crustose lichen 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 type specimen was collected by the authors in the Fazenda São Francisco, in a low-altitude primary rainforest. The lichen has a smooth and somewhat shiny, pale yellowish-grey thallus with a black prothallus line and covers areas of up to 7 cm (2.8 in) in diameter. The ascomata are pear-shaped (pyriform) and typically aggregate in groups of two to five, usually immersed in the bark tissue as pseudostromata. The ostioles of the ascomata contains lichexanthone, a lichen product that causes these structures to glow yellow when lit with a long-wavelength UV light. The main characteristic that distinguishes it from other members of Astrothelium are its ascospores, which measure 65–70 by 15–17 μm, and only have transverse septa.
Astrothelium flavomurisporum is a species of corticolous (bark-dwelling), crustose lichen 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 type specimen was collected by the authors from the Estação Ecológica de Cuniã, in a low-altitude primary rainforest. The lichen has a smooth and somewhat shiny, olive-green thallus that lacks a prothallus and covers areas of up to 7 cm (2.8 in) in diameter. The ascomata are pear-shaped (pyriform), measuring 0.5–0.7 mm in diameter, and typically aggregate in groups of two to five, usually quite immersed in the bark tissue. Ascospores are hyaline, ellipsoid, and muriform ; they measure 165–200 by 28–35 μm and have a thickened central septum. The presence of the lichen does not induce the formation of galls in the host. Thin-layer chromatography did not reveal the presence of any lichen products in the collected lichen samples. The characteristics that distinguish Astrothelium flavomurisporum from other members of Astrothelium include the dispersed groups of fused, immersed ascomata; and the median thickening of the ascospores.
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 nigrum is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It is characterized by its conical black pseudostromata, which contrast sharply with the thallus. This lichen species has been found only in Brazil and is unique in its appearance, superficially resembling a Pyrenula species.
Astrothelium novemseptatum is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It was first identified in Brazil, and has since been found in Guyana and Colombia. The lichen is characterized by its corticate, smooth, and somewhat shiny thallus, as well as its pyriform ascomata.
Astrothelium ochroleucoides is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. It is found in Brazil and Guyana.
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.
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 megeustomum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae, first scientifically 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.
