Biology:Malmidea volcaniana
| Malmidea volcaniana | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Lecanorales |
| Family: | Malmideaceae |
| Genus: | Malmidea |
| Species: | M. volcaniana
|
| Binomial name | |
| Malmidea volcaniana Kalb (2021)
| |
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| Holotype site: Cerro El Volcán, Venezuela[1] | |
Malmidea volcaniana is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae.[2] It is found in Venezuela. A major characteristic of the species is the coralloid (coral-shaped) clumps of isidia-like outgrowths on the thallus surface.
Taxonomy
The lichen was formally described as a new species in 2021 by the German lichenologist Klaus Kalb. The type specimen was collected from the Cerro El Volcán (Miranda), at an altitude of 1,460 m (4,790 ft). The species epithet refers to the type locality.[1]
Description
Malmidea volcaniana is a crustose lichen with a continuous thallus that ranges in thickness from 20 to 40 µm. The thallus is characterised by [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] formations that are more or less spherical and coalesce with age, forming [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] clumps of thin, isidia-like outgrowths. These formations are dull and vary in colour from greenish grey to ash-grey. The species has soralia that are more or less [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], measuring around 0.01 mm in diameter and intense orange-yellow in colour, emerging from warts that break off at the tips. These soralia react K+ (purple) and P+ (wine-red) to chemical spot tests.[1]
The medulla of the [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] and thallus is orange-yellow and also reacts to potassium hydroxide (K+ purple) and P+ (wine-red). The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] of this species is [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], with cells measuring 6–8 µm in diameter.[1]
Apothecia in Malmidea volcaniana are sessile and rounded, measuring between 0.3 and 0.8 mm in diameter and 0.2–0.3 mm in height. The apothecial [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] are initially flat but become distinctly convex with age, coloured beige to chocolate-brown. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is of the granifera-type, [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]], and ranges in colour from whitish and cream-coloured to greyish, typically paler than the disc. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is hyaline (translucent), while the medullary excipulum is orange-yellow and filled with opaque, orange-yellow anthraquinones, only partially dissolving in a solution of potassium hydroxide, with a K+ (golden-yellow to golden-orange) reaction.[1]
The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is around 20 µm high and light brown. The centrally located [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is 75–85 µm high, narrowing towards the margin, and is dark brown in colour, not reacting to potassium hydroxide (K−). The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is indistinct, and the hymenium measures 75–100 µm in height and is hyaline.[1]
The asci of Malmidea volcaniana are 50–60 µm by 15–20 µm in size, and each contains 6–8 [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]. These spores lack septa and are broadly ellipsoid with equally thickened walls and a [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] of 1–1.5 µm. The spores measure 11–17 by 7–10 µm.[1]
Chemically, this species contains emodin and emodic acid as major or somewhat major lichen products, atranorin and emodin bisanthrone as minor components, and some unknown xantholepinones.[1]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Kalb, Klaus (2021). "New or otherwise interesting lichens mainly from Brazil and Venezuela with special reference to the genus Malmidea". Archive for Lichenology 27: 1–41 [32]. http://www.fschumm.de/Archive/Vol%2027_Kalb_%20Brazil%20and%20Venezuela.pdf.
- ↑ "Malmidea volcaniana Kalb & J. Hern.". Species 2000: Naturalis, Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/B3BST.
Wikidata ☰ Q123983880 entry
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