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.
Leucodecton canescens is a species of lichen in the family Graphidaceae. Found in Sri Lanka, it was formally described as a new species in 2014 by lichenologists Gothamie Weerakoon, Robert Lücking and Helge Thorsten Lumbsch. The type specimen was collected from the Maussakanda Tea Estate at an altitude of 1,074 m (3,524 ft). The lichen, which has been recorded from several locations in the Central Province, grows in semi-exposed, disturbed areas at high elevations. The specific epithet canescens refers to the grey-coloured cover of the thallus.
Leucodecton fuscomarginatum is a species of lichen in the family Graphidaceae. Found in Sri Lanka, it was formally described as a new species in 2014 by lichenologists Gothamie Weerakoon, Robert Lücking and Helge Thorsten Lumbsch. The type specimen was collected from the Kikiliyamana Tea Estate at an altitude of 1,280 m (4,200 ft). The lichen, which is known to occur only at the type locality, grows in disturbed vegetation. The specific epithet fuscomarginatum refers to the rims of the ascomata pores, which are typically brown in colour. Leucodecton fuscomarginatum has a shiny, smooth, light greenish to yellowish brown thallus measuring 50–100 μm thick with a thin cortex. The ascospores are muriform, ellipsoid in shape, and measure 30–40 by 10–12 μm. Secondary chemicals present in the lichen include stictic acid, constictic acid, acetylconstictic acid, and hypostictic acid.
Ocellularia aptrootiana is a species of corticolous lichen in the family Graphidaceae. Found in Sri Lanka, it was formally described as a new species in 2014 by lichenologists Gothamie Weerakoon, Robert Lücking, and Helge Thorsten Lumbsch. The type specimen was collected from Mahailluppallama at an altitude of 170 m (560 ft). Here, in a low-altitude, dry, semi-evergreen forest, it was found growing around a water tank. The specific epithet aptrootiana honours Dutch lichenologist André Aptroot, "for his important contributions to tropical lichenology and his help with the research by the first author". Ocellularia aptrootiana has a grey, smooth to uneven or cracked thallus up to convert 5 cm (2 in) in diameter. The ascospores are hyaline, ellipsoid in shape, contain seven septa, and measure 20–25 by 6–7 μm. Secondary chemicals present in the lichen include psoromic acid, subpsoromic acid, and 2’-O-demethylpsoromic acids.
Rhabdodiscus isidiatus is a species of corticolous lichen in the family Graphidaceae. Found in Sri Lanka, it was formally described as a new species in 2014 by lichenologists Gothamie Weerakoon, Robert Lücking, and Helge Thorsten Lumbsch. The type specimen was collected from the Elkaduwa Plantation in Matale at an altitude of 915 m (3,002 ft). The lichen is only known to occur at the type locality, which is a patch of mid-elevation, disturbed montane forest. The specific epithet isidiatus refers to the presence of isidia on the thallus. Rhabdodiscus isidiatus has a cream-colored to white, smooth to uneven thallus up to 5 cm (2 in) in diameter. The ascomata are rounded and prominent, measuring 0.7–1.0 mm in diameter with a 0.3–0.5 mm wide pore and a light brown rim. Its ascospores are hyaline, ellipsoid in shape, contain three thick septa, and measure 12–15 by 5–6 μm. Secondary chemicals present in the lichen include psoromic acid, subpsoromic acid, and 2'-O-demethylpsoromic acid.
Astrothelium trypethelioides is a species of corticolous (bark-dwelling) lichen in the family Trypetheliaceae. Found in Venezuela, it was formally described as a new species in 2016 by André Aptroot. The type specimen was collected by Harrie Sipman along the Carapo River at an altitude of 800 m (2,600 ft). The lichen has a smooth, somewhat shiny, pale yellowish-grey thallus that covers areas of up to 9 cm (3.5 in). Its ascospores are hyaline, spindle-shaped (fusiform) with between 7 and 9 septa and dimensions of 49–52 by 13–16 µm. No lichen products were detected in the species using thin-layer chromatography.
Astrothelium mediocrassum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in Guyana, it was formally described as a new species in 2016 by Dutch lichenologist André Aptroot. The type specimen was collected by Harrie Sipman south of the Kuyuwini Landing at an altitude of 230 m (750 ft). The lichen has a somewhat shiny, smooth, pale green thallus that covers an area of up to 12 cm (4.7 in) in diameter. Its ascospores are hyaline, spindle-shaped (fusiform), and muriform, with dimensions of 70–80 by 22–25 µm. This is the smallest ascospore size of Astrothelia species. The middle, or median, septum of the spore is thickened in comparison with the others. No lichen products were detected using thin-layer chromatography. It is somewhat similar in appearance to Astrothelium octosporum, but that species has lichexanthone in its thallus and pseudostromata.
Astrothelium inspersogalbineum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in Singapore, it was formally described as a new species in 2016 by lichenologists André Aptroot and Gothamie Weerakoon. The type specimen was collected by the second author in a rainforest, where it was found growing on smooth bark. The lichen has a smooth and somewhat shiny, pale greenish-grey thallus with a cortex and a thin black prothallus line. It covers areas of up to 3 cm (1.2 in) in diameter, and does not induce gall formation in its host plant. A yellow to orange anthraquinone was the only lichen product detected in the collected specimens using thin-layer chromatography. A. inspersogalbineum also contains the compound lichexanthone, which causes the thallus to fluoresce yellow when lit with a long-wavelength UV light. The main characteristics of the lichen distinguishing it from others in Astrothelium are its inspersedhamathecium; its ascospores, with dimensions of 20–25 by 9–11 μm; and the grouping of its ascomata, which can fuse together to become irregularly confluent.
Astrothelium philippinense is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in the Philippines, it was formally described as a new species in 2016 by lichenologists André Aptroot and Felix Schumm. The type specimen was collected from Mount Talinis at an altitude between 1,100 and 1,600 m ; there, it was found in a rainforest growing on smooth tree bark. The lichen has a smooth and shiny, pale ochraceous-green thallus with a cortex and a thin brown to black prothallus line. It covers areas of up to 7 cm (2.8 in) in diameter. The presence of the lichen induces galls in the host plant, leading to the formation of numerous wart-like structures about 1–2 mm wide. No lichen products were detected in collected samples of the lichen using thin-layer chromatography. The combination of characteristics of the lichen that distinguish it from others in Astrothelium are the bullate, gall-like thallus; and the ascomata that are immersed in large thallus verrucae that are covered by thallus. The ascospores of A. philippinense number four per ascus. They are hyaline, ellipsoid, and muriform, with dimensions of 125–170 by 30–35 μm.
Astrothelium pseudannulare is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in Ecuador, it was formally described as a new species in 2016 by Dutch lichenologists André Aptroot and Javier Etayo. The type specimen was collected from the Podocarpus National Park at an altitude of 3,000 m (9,800 ft); there, it was found in a montane forest growing on smooth tree bark. The lichen has a smooth and shiny, olive-green thallus comprising patches of cortex that break through the host bark, covering areas about 1.0 to 3.5 mm in diameter. No lichen products were detected from collected samples of the lichen using thin-layer chromatography. The combination of characteristics of the lichen that distinguish it from others in Astrothelium are the rough thallus; the distribution of the ascomata, which ranges from solitary to irregularly confluent; and the form of the ascomata, which ranges from prominent to sessile. The ascospores are hyaline, spindle-shaped (fusiform), and have three septa; they measure 62–80 by 20–25 μm. The species epithet pseudannulare alludes to its resemblance to Astrothelium annulare, another species with large 3-septate spores.
Phlyctis lueckingii is a species of corticolous (bark-dwelling) lichen in the family Phlyctidaceae. Found in Sri Lanka, it was formally described as a new species by Gothamie Weerakoon and André Aptroot in 2016. The type was collected on the Dothalugala mountain, where it was found in a rainforest on the smooth bark of a tree. The species epithet honours lichenologist Robert Lücking.
Porina linearispora is a species of corticolous (bark-dwelling) lichen in the family Trichotheliaceae. 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 from the Parque Natural Municipal de Porto Velho, where it was found growing on bark in a primary rainforest. The lichen is distinguished from other members of genus Porina by its long and thin ascospores, for which the species is named.
Astrothelium conjugatum is a species of corticolous (bark-dwelling) crustose lichen in the family Trypetheliaceae, first described in 2016. It is known to occur in Sri Lanka.
Lecanactis minutissima is a species of corticolous (bark-dwelling), crustose lichen in the family Roccellaceae. Found in Sri Lanka, the lichen is characterised by its pale ochraceous thallus and sessile apothecia with dark brown discs, covered with thick white granular pruina.
Megalotremis cylindrica is a species of corticolous (bark-dwelling), lichen in the family Monoblastiaceae. It was described as a new species in 2016 based on a specimen collected from the Sinharaja Forest Reserve in Sri Lanka. The species is characterized by its unique pycnidia and absence of ascomata.
Schistophoron muriforme is a species of corticolous (bark-dwelling), crustose lichen in the family Graphidaceae, first described in 2016. Found in Sri Lanka, it is characterised by its pale yellowish-white thallus and muriformascospores.
Pyrenula multicolorata is a species of corticolous (bark-dwelling), crustose lichen in the family Pyrenulaceae, first described in 2016. It is distinguished by its almost superficial ascomata with a hamathecium inspersed with orange crystals, and ascospores that contain three internal partitions (septa).
Psoroglaena spinosa is a species of lichen in the family Verrucariaceae, first described in 2016. It is characterized by its small fruticose (bushy) thallus, which is corticate, smooth, dull, and bright green, covering small areas and consisting of tiny squamules that branch into somewhat moniliform threads.
Porina monilisidiata is a species of corticolous (bark-dwelling), crustose lichen in the family Trichotheliaceae, first described in 2016. This species is characterised by its shiny, olive-green thallus with numerous isidia and low conical ascomata.
Astrothelium longisporum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. It occurs in the Atlantic Forest of Brazil.
