Biology:Malmidea atlanticoides
| Malmidea atlanticoides | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Lecanorales |
| Family: | Malmideaceae |
| Genus: | Malmidea |
| Species: | M. atlanticoides
|
| Binomial name | |
| Malmidea atlanticoides Kalb & M.Cáceres (2021)
| |
| <mapframe zoom="3" frameless="1" align="center" longitude="-37.339444444444" latitude="-10.7675" height="200" width="270">{"type":"Feature","geometry":{"coordinates":[-37.339444444444446,-10.7675],"type":"Point"},"properties":{"title":"Malmidea atlanticoides","marker-color":"#5E74F3"}}</mapframe> | |
| Holotype site: Parque Nacional Serra de Itabaiana, Venezuela[1] | |
Malmidea atlanticoides is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae.[2] It is found in Brazil.
Taxonomy
It was formally described as a new species in 2021 by the lichenologists Klaus Kalb and Marcela Cáceres. The type specimen was collected by the authors from the Parque Nacional Serra de Itabaiana (pt) (Sergipe) at an elevation of 190 m (620 ft). The species epithet alludes to its resemblance to Malmidea atlantica, the species to which it was initially referred. Subsequent analysis revealed its chemical differences with this species. Malmidea atlanticoides is only known to occur at its type locality.[1]
Description
Malmidea atlanticoides is a crustose lichen with a continuous thallus measuring 75–100 µm in thickness. The thallus surface is [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (warty), featuring more or less spherical [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] that are 0.1–0.25 mm in diameter. The colour of the verrucae ranges from dull ash-grey to greenish-grey and light olive. Both soralia and isidia are absent in this species. The medulla of the verrucae and the thallus is orange-yellow, showing spot test reactions of K+ (orange to reddish) and P+ (vermilion). The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] with cells measuring 6–8 µm in diameter.[1]
The apothecia of Malmidea atlanticoides are sessile and rounded, with a diameter of 0.5–0.8 mm and a height of 0.3–0.4 mm. The apothecial [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] are flat to slightly concave, and their colour varies from beige to light brownish. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is of the granifera-type, initially [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] and becoming [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] with age. It is whitish to cream-coloured, bulging, and towers over the disc. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is hyaline, while the medullary excipulum is filled with orange-yellow hydrophobic granules that are nubilous and dissolve in KOH, producing a lemon-yellow efflux. The base of the apothecium reacts to K with an orange-red colour. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is approximately 25 µm high and light brown, while the centrally located [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is 80–100 µm high, narrowing towards the margin, and dark brown without reacting to K. The [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] is indistinct and the hymenium is hyaline, measuring 100–110 µm in height.[1]
The asci of Malmidea atlanticoides are 60–80 µm long and 15–20 µm wide. Each ascus contains four to eight [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] that lack septa. These ascospores are broadly ellipsoid, with equally thickened and [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] walls, measuring 12–15 by 8–9 µm with a [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] of 1–1.5 µm.[1]
Chemically, the species is characterised by the presence of atranorin as a major component, along with an unknown anthraquinone substance, detectable using thin-layer chromatography. Its lookalike, Malmidea atlantica, lacks both atranorin and the unknown anthraquinone.[1]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 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 [15]. http://www.fschumm.de/Archive/Vol%2027_Kalb_%20Brazil%20and%20Venezuela.pdf.
- ↑ "Malmidea atlanticoides Kalb & M. Cáceres". Species 2000: Naturalis, Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/B359Y.
Wikidata ☰ Q123983218 entry
 |  |
