| Macroconstrictolumina | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Dothideomycetes |
| Order: | Trypetheliales |
| Family: | Trypetheliaceae |
| Genus: | Macroconstrictolumina Lücking, R.Miranda & Aptroot (2020) |
| Type species | |
| Macroconstrictolumina malaccitula (Nyl.) Lücking, R.Miranda & Aptroot (2020) | |
| Species | |
M. lyrata Contents | |
Macroconstrictolumina is a genus of lichen-forming fungi in the family Trypetheliaceae. [1] It has four species. [2]
The genus was circumscribed in 2020 by lichenologists Robert Lücking, Ricardo Miranda-González, and André Aptroot. The genus name refers to its large ascospores . Three of the four species were previously in the genus Constrictolumina . Macroconstrictolumina is a sister taxon to Bogoriella , and all three genera are in the family Trypetheliaceae. [3]
The thallus, which is the vegetative body of the lichen, is typically whitish and lacks a cortex. It forms a symbiotic relationship with the green algae Trentepohlia , which serves as its photobiont . [3]
The ascomata, or spore-producing structures, of these fungi are usually singular but can sometimes be found in clusters. They are slightly raised or prominently emerging from the thallus, featuring a carbonised , hard outer layer. The opening of the ascomata, known as the ostiole, is typically at the top but occasionally found on the side. The involucrellum , a protective layer surrounding the ascomata, is also carbonised. [3]
The excipulum , which is the outer tissue layer of the ascomata, is made up of tightly interwoven cells, appearing brownish to colourless beneath the surface. The hamathecium , which is the tissue filling the cavity of the ascomata, consists of very thin, hyaline (transparent), branched, and interconnecting filaments called pseudoparaphyses , all set in a gel-like substance. [3]
The asci, or spore-bearing cells, are club-shaped, short-stalked, and open via a fissitunicate mechanism, meaning they have a double wall that splits to release spores. Each ascus typically contains two to eight spores and features a non-staining ocular chamber at its tip. [3]
The ascospores are spindle-shaped to ellipsoid, colourless, and have one to three cross-walls (septa) with occasional secondary constrictions in each cell. They often have a granular surface texture, are slightly pinched at the septa, and surrounded by a gel-like sheath. The spores are medium-sized, generally measuring 30–50 µm in length and 10–16 (sometimes up to 24) µm in width. However, in one species, M. lyrata, the spores are somewhat smaller. The reproductive structures known as pycnidia have not been observed in this genus. Chemical analysis using thin-layer chromatography has not detected any lichen products in these species. [3]
Macroconstrictolumina consists of lichen-forming fungi that predominantly inhabit terrestrial, lowland to lower montane tropical regions, often growing on bark. [3]
The Gomphillaceae are a family of lichen-forming fungi in the order Graphidales. Species in this family are found mostly in tropical regions.
Roccella is a genus of 23 species of lichens in the family Roccellaceae. The genus was circumscribed by Swiss botanist Augustin Pyramus de Candolle in 1805, with Roccella fuciformis as the type species.
The Trypetheliaceae are a family of mainly lichen-forming fungi in the order Trypetheliales. The family consists almost exclusively of corticolous (bark-dwelling), crustose lichens with an almost strictly tropical distribution.
Architrypethelium is a genus of lichen-forming fungi in the family Trypetheliaceae.
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.
Bathelium is a genus of lichen-forming fungi in the family Trypetheliaceae.
Astrothelium pseudomegalophthalmum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in Colombia, it was formally described as a new species in 2016 by Dutch lichenologist André Aptroot. The type specimen was collected from Araracuara at an altitude of 300 m (980 ft); there, in a savanna forest, it was found growing on smooth tree bark. The lichen has a smooth and somewhat shiny, pale olive-green thallus with a cortex and a thin black prothallus line. The lichen thallus covers areas of up to 7 cm (2.8 in) in diameter, and its presence does not induce the formation of galls in the host plant. No lichen products were detected in collected samples using thin-layer chromatography. The characteristics of the lichen that distinguish it from others in Astrothelium are its solitary to irregularly confluent ascomata, which are erumpent with an exposed upper part. Its ascospores have seven septa and measure 152–166 by 32–37 μm. Its namesake species, A. megalophthalmum, also has large spores with seven septa.
Astrothelium curvisporum 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, olive-green to olive-brown thallus that lacks a 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 the host. The ascomata are more or less spherical (globose), measuring 0.8–1.2 mm in diameter, and typically occur in groups of 3 to 15, usually immersed in pseudostromata. The species epithet curvisporum refers to the curved ascospores, which have five septa that divide the spore into distinct compartments. The spores have a thick gelatinous layer that is 17–22 μm thick. No lichen products were detected in collected samples of the species using thin-layer chromatography. The characteristics that distinguish A. curvisporum from other members of Astrothelium include its grouped ascomata and its curved ascospores.
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 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.
Architrypethelium hyalinum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in Costa Rica and Brazil, it was formally described as a new species in 2008 by lichenologist André Aptroot. The type specimen was collected by Harrie Sipman from the Las Cruces Biological Station in Puntarenas. The lichen has a smooth to uneven, olive-green thallus. Its ascomata occur solitarily, have an apical ostiole, and measure 0.7–1.5 mm in diameter. Ascospores number 4 to 8 per ascus, have an oblong to ellipsoid shape with 3 septa, and measure 100–150 by 30–50 μm. These spores are among the largest of the 3-septate lichens in the Trypetheliaceae. Both the thallus and ascomata contain lichexanthone, a lichen product that causes these structures to glow yellow when lit with a long-wavelength UV light; A. hyalinum is the only species in genus Architrypethelium that contains lichexanthone.
Nigrovothelium is a genus of lichen-forming fungi in the family Trypetheliaceae. It has three species. The genus was circumscribed in 2016 by lichenologists Robert Lücking, Matthew Nelsen, and André Aptroot, to contain species formerly in the Trypethelium tropicum species group. The type species, Nigrovothelium tropicum, was originally described by Erik Acharius in 1810, as a species of Verrucaria.
Dictyomeridium is a genus of corticolous (bark-dwelling), crustose lichens in the family Trypetheliaceae. It has eight species.
Clandestinotrema is a genus of lichen-forming fungi in the family Graphidaceae. It has 17 species. They typically inhabit montane and cloud forest at higher elevations in the tropics.
Cryptoschizotrema is a genus of lichen-forming fungi in the family Graphidaceae. It has two species. The genus was circumscribed in 2019 by lichenologists André Aptroot, Robert Lücking, and Marcela Cáceres. The genus name alludes to the similarity in anatomy with Schizotrema species. This resemblance is due to the partially carbonized, concentrically layered, and fissured excipulum, which gives the impression that the Schizotrema-like excipulum is concealed beneath a protective layer. The type species was originally described by William Nylander in 1867, as a species of Thelotrema.
Astrothelium chulumanense is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae. Found in the Yungas montane forest of Bolivia, it was formally described as a new species in 2023. It is characterized by pseudostromata not differing in colour from the thallus, perithecia immersed for the most part in the thallus with the upper part elevated above and covered with orange pigment, apical and fused ostioles, the absence of lichexanthone, a clear hamathecium, eight-spored asci, and large, muriform ascospores with a thickened median septum.
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.
Protothelenella is a genus of fungi in the family Protothelenellaceae. It contains 11 species, some of which form lichens. Protothelenella species have a crustose thallus with spherical to pear-shaped, dark brown to blackish perithecia. Microscopic characteristics of the genus include bitunicate asci with an amyloid tholus, and ascospores that are colourless and contain multiple internal partitions. Some species grow on acidic substrates including rocks, soil, bryophytes, plant detritus or rotten wood. Other species are lichenicolous (lichen-dwelling), growing on species of Solorina, Peltigera, Pseudocyphellaria, or Cladonia.
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.
Allographa anguilliradians is a species of corticolous (bark-dwelling), crustose lichen in the family Graphidaceae. It has been found in Trinidad and Tobago and Central-West Brazil. Its thallus covers an area of 3 to 7 cm in diameter with a slim profile and a variable surface texture, with a distinct metallic pale grey-olive colour without a prothallus. Its reproductive structures, known as lirellae, form a star-like pattern with black, carbonised outer layers and clear, colourless hymenium, while its ascospores are oblong and segmented, reacting violet-blue to iodine-based stains.