Polymeridium is a genus of lichen-forming fungi in the family Trypetheliaceae. Species in the genus are corticolous (bark-dwelling) and typically occur in tropical areas.
Enterographa lichexanthonica is a species of crustose and corticolous (bark-dwelling) lichen in the family Roccellaceae. Found in the Brazilian Amazon, it was formally introduced as a new species in 2017 by lichenologists Marcela Eugenia Cáceres and André Aptroot. The type specimen was collected by the authors from the Adolfo Ducke Forest Reserve, along trails near a field station; here, it was found growing on tree bark in a old-growth rainforest. The lichen has a thin, dull, pale greenish thallus surrounded by a thin black prothallus. Its ascospores are hyaline, have seven septa, and measure 21–27 by 5–6 μm; they have a 1 μm-thick gelatinous sheath surrounding them. The specific epithet lichexanthonica refers to lichexanthone, a secondary chemical that occurs in the cortex of the lichen. This compound causes the lichen to fluoresce yellow when a UV light is shone upon it. Enterographa lichexanthonica is morphologically similar to E. kalbii, but this latter species has lichexanthone only on the ascomata, not on the thallus.
Acanthothecis submuriformis is a species of corticolous (bark-dwelling) lichen in the family Graphidaceae. Found in Brazil, it was formally described as a new species in 2022 by André Aptroot, Robert Lücking, and Marcela Eugenia da Silva M.Cáceres. The type specimen was collected from the Parque Natural Municipal ; here the lichen was found growing on tree bark in primary rainforest.
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 bivelum 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 Parque Natural Municipal de Porto Velho, in a primary rainforest. The lichen has a smooth and somewhat shiny, ochraceous-green thallus with a 0.4 cm-wide rough and irregular prothallus; the thallus covers areas of up to 3 cm (1.2 in) in diameter. The presence of the lichen does not induce the formation of galls in the host. The ascomata are pear-shaped (pyriform), measure 0.5–0.7 mm in diameter, typically aggregate in groups of two to six, and are usually immersed in the bark tissue. The characteristics that distinguish it from other members of Astrothelium include the diffusely pseudostromatic, erumpent ascomata that are covered by thallus and have an external pink pigment, with each containing a single group of fused ascomata; and the 5-septate ascospores. A. bivelum is one of the few Astrothelium-like species with 5-septate ascospores that does not contain lichexanthone.
Astrothelium duplicatum 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 Parque Natural Municipal de Porto Velho, where it was found growing on the smooth bark of a tree in a park near a rainforest, and on tree twigs in the forest. The lichen has a smooth and somewhat shiny, olive-green thallus surrounded by a black prothallus and covers areas of up to 5 cm (2 in) in diameter. The presence of the lichen does not induce the formation of galls in its host. The ascomata are roughly spherical and typically aggregate in groups of about five to fifty, usually immersed in the bark tissue as pseudostromata. Its ascospores are hyaline, spindle-shaped and measure 45–55 by 11–15 μm. The use of thin-layer chromatography on collected lichen samples revealed the presence of an anthraquinone compound, possibly parietin. The characteristics that distinguish Astrothelium duplicatum from other members of Astrothelium include the internal, yellow pigment of its ascomata; and the dimensions of its ascospores, which are about 3–4 times as long as they are broad. Astrothelium mesoduplex is similar in appearance, but that species lacks yellow to orange pseudostromata and has shorter ascospores.
Astrothelium eustomurale 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 Parque Natural Municipal de Porto Velho, in a low-altitude primary rainforest. The lichen has a smooth and somewhat shiny, pale yellowish-grey thallus that lacks a prothallus and covers areas of up to 12 cm (4.7 in) in diameter. The presence of the lichen does not induce the formation of galls in the host. The ascomata are pear-shaped (pyriform) and typically occur in aggregates of two to five, usually immersed in the bark tissue under the pseudostromata and with a whitish-coloured tissue that contrasts with the surrounding thallus. Black pycnidia are abundant on the pseudostromata. The area around and including the ostiole of the ascomata contains lichexanthone, a lichen product that causes these areas to glow yellow when lit with a long-wavelength UV light. The characteristics that distinguish it from other members of Astrothelium include the UV+ yellow nature of the ostiole; and the fused, erumpent pseudostromatic ascomata that have a white cover contrasting it with the thallus colour.
Calopadia granulosa is a species of corticolous (bark-dwelling), crustose lichen in the family Pilocarpaceae. Found in Brazil, it was formally described as a new species in 2014 by lichenologists André Aptroot and Marcela Cáceres. The type specimen was collected by the authors from the Parque Natural Municipal de Porto Velho (Rondônia), where it was found growing on the smooth bark of a tree in a park near a rainforest. The thallus of the lichen consists of a crust of pale greyish-green granules that lacks a prothallus. Its ascospores, which number one per ascus, are hyaline, ellipsoid, and muriform. They measure 33–38 by 10.5–13.0 μm; these are among the smallest ascospores found in the genus Calopadia.
Anisomeridium lateriticum is a species of saxicolous (rock-dwelling) lichen in the family Monoblastiaceae. Found in Brazil, it was formally described as a new species in 2013 by lichenologists André Aptroot and Marcela Cáceres. The type specimen was collected by the authors in Fazenda São Francisco north of Porto Velho (Rondônia), where it was found growing on lateritic rock in a primary rainforest.
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 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.
Enterographa rotundata is a species of corticolous (bark-dwelling) crustose lichen in the family Roccellaceae. This species was discovered in Brazil, growing on the smooth bark of trees in the Brazilian Caatinga forest. It has round apothecia, a feature that sets it apart from most of its kind.
Herpothallon tricolor is a rare species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in South Brazil, it was described as a new species in 2017. It is distinguished from others species in genus Herpothallon by its unique colouration: a combination of a grey thallus with a bright red hypothallus and orange-tipped pseudoisidia.
Neosergipea is a genus of lichen-forming fungi in the family Roccellaceae. It has four species, all of which are corticolous (bark-dwelling), crustose lichens that are found in the tropical forests of Brazil. This genus is related to the genera Dichosporidium, Enterographa, and Erythrodecton. It distinguishes itself through unique morphological characteristics and certain chemical constituents, in particular, its non-carbonised ascomata and the presence of a vivid orange anthraquinone compound.
Neosergipea bicolor is a rare species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found only in Brazil and described as a new species in 2017, Neosergipea bicolor is characterised its dual-coloured appearance.
Neosergipea hyphosa is a species of corticolous (bark-dwelling) lichen in the family Roccellaceae. This lichen species is uniquely characterised by its olive-green thallus—a type of vegetative tissue—and spherical ascomata, or fungal reproductive structures. It is most commonly found on tree bark in Brazil. The name hyphosa alludes to the distinct hyphose surface of the thallus.
Nyungwea pycnidiata is a rare species of lichen in the family Opegraphaceae. Found in the North Region of Brazil, it was described as a new species in 2017. It is unique for its adaptation to living on termite nests.
Opegrapha ramisorediata is a rare species of corticolous (bark-dwelling), crustose lichen in the family Opegraphaceae. Known to occur only in northeastern Brazil, it was described as a new species in 2017. It is characterised by a thin, pale greenish-mauve thallus.
