Biology:Allographa anguilliradians
| Allographa anguilliradians | |
|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Graphidales |
| Family: | Graphidaceae |
| Genus: | Allographa |
| Species: | A. anguilliradians
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| Binomial name | |
| Allographa anguilliradians Lücking ex Lücking (2018)
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| Synonyms | |
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Allographa anguilliradians is a species of corticolous (bark-dwelling), crustose lichen in the family Graphidaceae.[1] 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 [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], form a star-like pattern with black, [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] outer layers and clear, colourless hymenium (fertile spore-bearing tissue), while its [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] are oblong and segmented, reacting violet-blue to iodine-based stains.
Taxonomy
Allographa anguilliradians was initially described as Graphis anguilliradians by Robert Lücking in 2009.[2] However, this was a nomen invalidum designation, meaning the taxon was not validly published.[3] The species was formally described and validly published in the genus Allographa by Lücking in 2018.[4]
Description
The thallus of Allographa anguilliradians has a corticolous (tree-bark dwelling) and crustose (crust-like) form. It extends over an area measuring between 3 and 7 cm (1.2 and 2.8 in) in diameter and maintains a slim profile with a thickness ranging from 50 to 100 μm. The surface texture of the thallus is variable, ranging from smooth to slightly irregular, and it has a distinct metallic pale grey-olive colouration. This lichen lacks a [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], which is a characteristic growth edge found in some lichen species.[4]
Upon examining a cross-section of the thallus, several key features are observable. The uppermost layer, known as the cortex, is [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], providing a somewhat tough and rubbery texture. Beneath this layer lies an irregularly distributed [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], essential for the lichen's photosynthetic activity. Additionally, the thallus contains clusters of calcium oxalate crystals.[4]
The reproductive structures, known as [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], are [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (wavy) and show radial branching, creating a star-like pattern. These lirellae are conspicuous and characterised by their thin yet complete [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] at the apex. They vary in size, measuring 3 to 10 mm in length and 0.15 to 0.25 mm in width. The reproductive [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] of the lirellae is concealed, and the surrounding labia (edge structures) are entirely black. However, due to the thin overlying thallus cover, they may appear dark grey. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], or the outermost layer of the lirellae, is completely [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] and measures 50 to 100 μm in width. It is enveloped laterally by a [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], algae-containing thallus layer, which also includes crystal clusters.[4]
The hymenium, the spore-bearing layer within the lirellae, is clear and colourless, with a height ranging between 130 and 170 μm. The paraphyses within the hymenium are [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] and unbranched. The asci, the spore-containing structures, are [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (spindle-shaped) and vary in size from 120 to 150 μm in length and 20 to 25 μm in width. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] produced by Allographa anguilliradians are oblong and segmented, having 9 to 13 septa. These spores measure 50 to 70 by 8 to 11 μm and are colourless. They have a violet-blue reaction when subjected to an iodine-based stain. Thin-layer chromatography, a technique used to identify chemical substances, did not detect any lichen products in this species.[4]
Habitat and distribution
The type locality of Allographa anguilliradians is in Trinidad and Tobago, specifically in Trinidad, Tunapuna–Piarco, on the ridge from the summit of Morne Bleu to Lalaja-Paria Trail in the Northern Range, between Arima and Blanchisseuse. The holotype was collected in October 1963 by Henry Imshaug.[4] It was recorded from Mato Grosso do Sul, Brazil, in 2022.[5]
References
- ↑ "Allographa anguilliradians Lücking". Species 2000: Naturalis, Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/BWRJ.
- ↑ Lücking, Robert; Archer, Alan W.; Aptroot, André (2009). "A world-wide key to the genus Graphis (Ostropales: Graphidaceae)". The Lichenologist 41 (4): 363–452 [408]. doi:10.1017/s0024282909008305.
- ↑ "Record Details: Graphis anguilliradians Lücking, Lichenologist 41(4): 338 (2009)". Index Fungorum. https://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=638123.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Lücking, Robert; Kalb, Klaus (2018). "Formal instatement of Allographa (Graphidaceae): how to deal with a hyperdiverse genus complex with cryptic differentiation and paucity of molecular data". Herzogia 31 (1): 535–561. doi:10.13158/heia.31.1.2018.535.
- ↑ Aptroot, André; Souza, Maria Fernanda de; Cáceres, Marcela Eugenia da Silva; Santos, Lidiane Alves dos; Spielmann, Adriano Afonso (2022). "New lichen records from Brazil". Archive for Lichenology 31: 1–51 [3]. http://fschumm.de/Archive/Vol%2031_Aptroot_new%20records.pdf.
Wikidata ☰ Q104759911 entry
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