| 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) | |
 | |
| 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.
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 (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]
Malmidea atlanticoides is a crustose lichen with a continuous thallus measuring 75–100 µm in thickness. The thallus surface is verrucose (warty), featuring more or less spherical verrucae 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 photobiont is chlorococcoid 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 discs are flat to slightly concave, and their colour varies from beige to light brownish. The excipulum is of the granifera-type, initially entire and becoming granular with age. It is whitish to cream-coloured, bulging, and towers over the disc. The ectal excipulum 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 subhymenium is approximately 25 µm high and light brown, while the centrally located hypothecium is 80–100 µm high, narrowing towards the margin, and dark brown without reacting to K. The epihymenium 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 ascospores that lack septa. These ascospores are broadly ellipsoid, with equally thickened and halonate walls, measuring 12–15 by 8–9 µm with a halo 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]
Malmidea is a genus of crustose lichens and the type genus of the family Malmideaceae. It was established in 2011 to contain a phylogenetically distinct group of species formerly placed in the genus Malcolmiella. The crust-like thallus of Malmidea lichens has a surface that varies from smooth to rough, featuring textures such as verrucose (wart-like), granulose (grainy), or pustulate (pimpled). These textures are often formed by goniocysts, which are spherical clusters of green algal cells from the family Chlorococcaceae, encased in fungal hyphae. Malmidea comprises nearly 70 mostly tropical species that grow on bark, although a few grow on leaves.
Topeliopsis acutispora is a species of crustose lichen in the family Graphidaceae. It is found in New South Wales and southern Queensland (Australia), where it grows on bryophytes.
Maronora is a monotypic fungal genus in the family Fuscideaceae. It contains the single species Maronora cyanosora, a corticolous (bark-dwelling) lichen. It is characterised by its distinctive bluish-grey circular soralia on the thallus, Lecanora-like apothecia, and simple, hyaline ascospores.
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.
Malmidea cineracea is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Nicaragua.
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.
Lecanactis malmideoides is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Roccellaceae. First described in 2018, it is found in Brazil. Characteristics of the lichen include its pruinosediscs, thin and glossy black margins, and ascospore structure.
Malmidea albomarginata is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela.
Malmidea allobakeri is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela.
Malmidea allopapillosa is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela.
Malmidea hechicerae is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela.
Malmidea hernandeziana is a little-known species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela. The distinctive features of this species include a thallus with coralloid-like outgrowths, light-coloured fruiting bodies (ascomata) with a specialised structural layer, relatively large spores that tend to have slightly thickened walls at their ends, and the absence of specific lichen products typically found in other species of the genus. This combination of characteristics sets Malmidea hernandeziana apart from other species in the genus Malmidea.
Malmidea isidiifera is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Brazil and Venezuela.
Malmidea leucopiperis is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Brazil.
Malmidea rhodopisoides is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Brazil.
Malmidea subcinerea is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela. The lichen has a smooth, dull thallus varying in colour from grey to olive, with a white internal medulla. It has sessile, rounded apothecia with light beige to greyish-brown discs.
Malmidea volcaniana is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. 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.
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 graphicum is a species of lichen in the family Trypetheliaceae. This lichen features an extended, reticulate pseudostroma that is lower than its slightly bullate thallus.
Enterographa aldabrensis is a species of corticolous (bark-dwelling), crustose lichen in the family Roccellaceae. It is only known to occur in Aldabra in the Seychelles.