Byssotrema

Last updated

Byssotrema
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Graphidales
Family: Graphidaceae
Genus: Byssotrema
M.Cáceres, Aptroot & Lücking (2014)
Species:
B. mirabile
Binomial name
Byssotrema mirabile
M.Cáceres, Aptroot & Lücking (2014)
Byssotrema
Holotype: Cuniã Ecological Station, Brazil [1]

Byssotrema is a monotypic fungal genus in the subfamily Graphidoideae of the family Graphidaceae. [2] It contains the single species Byssotrema mirabile, a little-known corticolous (bark-dwelling), crustose lichen found only in Brazil.

Contents

Taxonomy

Both the genus Byssotrema and its single species were described as new to science in 2014 by the lichenologists Marcela Cáceres, André Aptroot, and Robert Lücking. The type specimen of Byssotrema mirabile was collected in from the Cuniã Ecological Station (Rondônia), at kilometer 760 on road BR 319, northwest of Porto Velho, at an elevation of 100 m (330 ft). The specimen was found growing on tree bark in a primary rainforest on 13 March 2012 by Cáceres and Aptroot. [1]

The genus name Byssotrema is derived from the Greek βύσσα, meaning "fine and soft fabric". [3] The ending –trema is derived from the Greek neuter noun τρημα, meaning "perforation; aperture; opening; orifice", [4] and refers to the widely open ascomata that are characteristic of the genus. [1]

Description

The thallus of Byssotrema mirabile can reach up to about 5 cm (2 in) in diameter and has a continuous, smooth surface with a greenish-grey colour. The thallus lacks a prothallus (a distinct boundary layer). In cross-section, the thallus is 70–100 μm thick and comprises a prosoplectenchymatous cortex (a type of cellular structure) 15–20 μm thick, a photobiont layer 30–40 μm thick, and a medulla 30–40  μm thick. The medulla contains numerous small, grey crystals that do not dissolve in potassium hydroxide solution. The photobiont , or photosynthetic partner, is from the green algal genus Trentepohlia , with cells that are rounded to irregular in shape, arranged in irregular groups, and yellowish-green in colour, measuring 7–11 by 6–9 μm. [1]

The ascomata (fruiting bodies) are rounded to angular, prominent to sessile , and measure 0.5–1 mm in diameter and 0.4–0.5 mm in height. They feature a nearly complete, steeply sloping thalline margin that is smooth and greyish-green, with a distinct proper margin that appears as a thick, white rim around the pore. The disc of the ascomata is partially exposed, light brown, translucent, and thinly white- pruinose (having a frost-like appearance). [1]

The excipulum (the outer layer of the ascomata) is apically carbonized , with orange-brown lateral and basal portions, 30–50 μm wide. It is covered laterally by an algiferous (algae-bearing), corticate thallus that lacks periderm layers and is 60–90 μm thick. The hypothecium (the layer below the hymenium) is prosoplectenchymatous, 10–15 μm high, and hyaline to yellowish. The hymenium (the spore-bearing layer) is 90–100 μm high, hyaline, and strongly inspersed (infused with granules), which rapidly dissolve in potassium hydroxide. The epithecium (the uppermost layer of the hymenium) is indistinct, 5–10 μm high, and hyaline. [1]

The paraphyses (sterile filaments in the hymenium) are unbranched and smooth at the tips. The asci (spore sacs) are fusiform to clavate , measuring 80–90 by 10–12 μm. Each ascus contains 8 ellipsoid ascospores, which are 3-septate, measuring 11–15 by 6–7 μm, and 1.8–2.5 times as long as wide. The ascospores are hyaline, distoseptate with lens-shaped lumina, and react violet-blue with iodine. [1]

Habitat and distribution

Byssotrema mirabile is exclusively found in the primary rainforests of Rondônia, Brazil, where it grows in the shaded understory of rainforest environments undisturbed by man. It is only known to occur at its type locality. [1]

Related Research Articles

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.

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 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 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.

Cruentotrema amazonum is a little-known species of script lichen in the family Graphidaceae. It is found in Brazil, Thailand, and Vietnam, where it grows in the understory of primary rainforests.

Fissurina amazonica is a little-known species of corticolous (bark-dwelling) script lichen in the family Graphidaceae. Found in Brazil, it is a shade-loving species that thrives in the understory of undisturbed rainforests.

Fissurina amyloidea is a little-known species of script lichen in the family Graphidaceae. It is found in the primary rainforests of Rondônia, Brazil. It is characterized by its weakly carbonizedlirellae and thick-walled, strongly amyloid ascospores. Despite its superficial similarity to Fissurina subfurfuracea, F. amyloidea exhibits unique anatomical features that set it apart from other species within the genus.

Fissurina chrysocarpa is a little-known species of script lichen in the family Graphidaceae. Found primarily in the rainforests of Rondônia, Brazil, it is distinguished by its bright orange lirellae.

Fissurina duplicans is a little-known species of corticolous (bark-dwelling) script lichen in the family Graphidaceae. It is found in primary rainforests of Brazil. The lichen has an endoperidermal thallus and a double margin of lirellae, setting it apart from similar species.

Ocellularia vulcanisorediata is a rare species of corticolous (bark-dwelling) lichen in the family Graphidaceae. Described as a new species in 2014, it is only known to occur in Puerto Rico.

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.

Astrothelium tetrasporum is a species of corticolous (bark-dwelling), crustose lichen in the family Trypetheliaceae, first described in 2016. It is found in Brazil.

Caloplaca lecanorocarpa is a species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. Found in Brazil, it was formally described as a new species in 2016 by the lichenologists André Aptroot and Marcela Cáceres. It is named for its overall appearance to lichens in the Lecanora subfusca species complex.

<i>Glaucotrema</i> Genus of lichens

Glaucotrema is a genus of lichen-forming fungi in the family Graphidaceae. It has five species.

Malmographina is a fungal genus in the family Graphidaceae. The genus is monotypic, containing the single species Malmographina plicosa, a script lichen found in South America. Genus Malmographina is characterised by its smooth, olive-green thallus, erumpent to prominent lirellae with orange to cinnabar-red pigment, a clear hymenium, and hyaline, non-amyloid ascospores.

Corticorygma is a monotypic fungal genus in the subfamily Graphidoideae of the family Graphidaceae. It contains a single species, the corticolous (bark-dwelling) crustose lichen Corticorygma stellatum. This script lichen is found in the shaded understory of rainforests in the Brazilian states of Rondônia and Paraná.

References

  1. 1 2 3 4 5 6 7 8 Cáceres, Marcela; Aptroot, André; Parnmen, Sittiporn; Lücking, Robert (2014). "Remarkable diversity of the lichen family Graphidaceae in the Amazon rain forest of Rondônia, Brazil". Phytotaxa. 189 (1): 87–136 [91]. doi:10.11646/phytotaxa.189.1.8.
  2. "Byssotrema". Catalogue of Life . Species 2000: Leiden, the Netherlands. Retrieved 17 May 2024.
  3. Ulloa, Miguel; Aguirre-Acosta, Elvira (2020). Illustrated Generic Names of Fungi. St. Paul, Minnesota: APS press. pp. 56–57. ISBN   978-0-89054-618-5.
  4. Pennycook, Shaun R. (2022). "Gender of fungal generic names ending in –trema". Mycotaxon. 137 (3): 545–554. doi: 10.5248/137.545 .