| Tamasia | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Lecanorales |
| Family: | Ramalinaceae |
| Genus: | Tamasia Farkas (2023) |
| Species: | T. fijiensis |
| Binomial name | |
| Tamasia fijiensis Farkas (2023) | |
Tamasia is a fungal genus in the family Ramalinaceae. [1] It comprises the single species Tamasia fijiensis, a foliicolous (leaf-dwelling) crustose lichen. [2]
The genus Tamasia was circumscribed by the Hungarian lichenologist Edit Éva Farkas in 2023, who named it in honour of the Hungarian botanist Tamás Pócs, an expert on tropical plants and cryptogamic organisms. [2]
The genus differs from the related Bacidina by having wider 1-septate ascospores and a characteristic ascus apex structure. It can be distinguished from Megalaria by its different hymenial pigmentation, exciple structure, and thin-walled ascospores with slight constrictions at the septa. [2]
The type specimen was collected in 2003 from mossy elfin forest at an elevation of 990–1,010 metres on Viti Levu, Fiji. At the time of its original publication, the genus was known only from its type locality in Fiji, giving it a restricted Paleotropical distribution. [2]
Tamasia fijiensis is a foliicolous lichen, meaning it grows on the surface of living leaves. It forms a distinctive violet-coloured crust on its leaf substrate. This violet colouration comes from its photobiont (the photosynthetic partner in the lichen symbiosis), which is a cyanobacterium belonging to the genus Rhizonema . The surface of the lichen appears slightly rough and uneven, with wavy lines created by chains of these cyanobacterial cells. [2]
The reproductive structures (apothecia) are small, disc-shaped organs measuring 0.3–0.4 millimetres across. These appear as pale orange to cream-coloured discs attached directly to the lichen's surface. Each disc is surrounded by a rim (called an exciple ) that is made up of tightly packed fungal cells, giving it a tissue-like appearance under the microscope. [2]
Inside the apothecia, the fungal partner produces spores within elongated sacs called asci. These asci have a distinctive internal structure that can be seen when stained with iodine solution, showing a characteristic pattern (known as the Tamasia-type) that helps distinguish this genus from its relatives. The asci are interspersed with thread-like structures called paraphyses, which are usually unbranched but occasionally split near their tips, where they become noticeably thickened. [2]
Each ascus contains eight spores. These spores are elliptical in shape and divided into two cells by a single cross-wall (septum), measuring 6–8 micrometres long by 3–4 micrometres wide. The spores have relatively thin walls and show a slight pinching at the septum. [2]
Tamasia fijiensis is known only from a single location in Fiji, specifically from the cloud forests of Viti Levu, the largest island in the Fijian archipelago. The species was first discovered in 2003 in what is known locally as mossy elfin forest, a distinctive type of tropical montane forest characterised by its low canopy and abundance of epiphytes. [2]
The type locality where the species was found lies at an elevation of 990–1,010 metres above sea level. At this altitude, the forest is frequently enveloped in clouds, creating consistently humid conditions that are particularly favourable for foliicolous lichens. The forest canopy in this habitat is dominated by Cyathea tree ferns and Alpinia boia , a tall member of the ginger family that grows to 3–4 metres in height. [2]
As a foliicolous lichen, T. fijiensis grows on the living leaves of vascular plants in the understory of this cloud forest, though the specific host plant species has not been identified. This highly specialised habitat requirement, combined with its currently known restricted range, suggests that T. fijiensis may be endemic to the high-altitude forests of Fiji. However, similar high-elevation tropical forests exist elsewhere in the South Pacific region, and future surveys may reveal the species to be present in other locations. [2]
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores, produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or species can occur in numbers of one, two, four, or multiples of four. In a few cases, the ascospores can bud off conidia that may fill the asci with hundreds of conidia, or the ascospores may fragment, e.g. some Cordyceps, also filling the asci with smaller cells. Ascospores are nonmotile, usually single celled, but not infrequently may be coenocytic, and in some cases coenocytic in multiple planes. Mitotic divisions within the developing spores populate each resulting cell in septate ascospores with nuclei. The term ocular chamber, or oculus, refers to the epiplasm that is surrounded by the "bourrelet".
The Pertusariales are an order of fungi in the class Lecanoromycetes, comprising 8 families, 31 genera, and over 600 species, many of which form lichens. This diverse group is characterized by complex taxonomic history and ongoing phylogenetic revisions. Originally proposed by Maurice Choisy in 1949 and later formally published by the lichenologists David L. Hawksworth and Ove Eriksson in 1986, Pertusariales has undergone significant reclassification due to molecular phylogenetics studies. The order includes well-known genera such as Pertusaria and Ochrolechia, as well as families like Megasporaceae and Icmadophilaceae.
Japewia is a genus of lichen-forming fungi in the family Lecanoraceae. The genus was circumscribed in 1990 by the Norwegian lichenologist Tor Tønsberg, who assigned J. tornoënsis as the type species. The new genus is named in honour of Peter Wilfred James, a notable lichenologist, with Japewia being derived from the first letters of his initials (Ja) and his surname (Pe) followed by a typical Latin suffix (-wia).
Badimiella is a genus of lichen-forming fungi in the family Pilocarpaceae. It has two species of foliicolous (leaf-dwelling) lichens.
Mazosia is a genus of lichen-forming fungi in the family Roccellaceae.
Podotara is a fungal genus in the family Pilocarpaceae. It is a monotypic genus, containing the single species Podotara pilophoriformis, an uncommon foliicolous (leaf-dwelling), crustose lichen that grows on Podocarpus totara, a species of podocarp tree endemic to New Zealand. Both the genus and the species were proposed in 1996.
Fauriea is a genus of lichen-forming fungi in the family Teloschistaceae. The genus, which contains seven species, is a member of the subfamily Caloplacoideae.
Caloplaca letrouitioides is a little-known species of corticolous (bark-dwelling), crustose lichen belonging to the family Teloschistaceae, described in 2011. It is known to occur in Victoria, Australia. The species was named for its superficial resemblance to species in the genus Letrouitia. The anatomical characteristics of Caloplaca letrouitioides, particularly the well-developed true exciple and the unexpanded paraphyses tips, along with the absence of algae in the apothecia, set it apart from other species in the genus.
Megalospora austropacifica is a species of corticolous (bark-dwelling), crustose lichen in the family Megalosporaceae. It is found on the islands of Taveuni and Viti Levu in Fiji. It has a yellowish grey to whitish grey, glossy thallus that is thick and may appear slightly wrinkled or smooth, often with irregular cracks and small papillae containing conidiomata, but lacking isidia and soredia. Its apothecia are circular, up to 4.5 mm in diameter, with the disc evolving from concave to slightly convex and coloured from orange-brown to red-brown, surrounded by a thick, prominent margin.
Chaenothecopsis kilimanjaroensis is a species of lichenicolous (lichen-dwelling) pin lichen in the family Mycocaliciaceae. Found in the cloud forests of Tanzania, it was described as a new species in 2019. These tiny lichens have a short stalk, which can be either single or formed in aggregates on the same thallus. The stalks are medium brown at the base and become translucent in water. This species has unique spores, which contain a single septum, are arranged in a single row in the ascus, and have a surface ornamented with elongated, blister-like structures.
Harusavskia is single-species fungal genus in the family Teloschistaceae. It contains the little-known species Harusavskia elenkinianoides, a saxicolous (rock-dwelling), crustose lichen. This species is known only from its original collection site near the Laguna del Maule in Chile.
Glaucomaria is a genus of lichen-forming fungi in the family Lecanoraceae. It has seven species. The genus was circumscribed by Maurice Choisy in 1929. It contains crustose lichens formerly placed in the Lecanora rupicola species complex as defined by several previous authors.
Tapellaria intermedia is a little-known species of foliicolous (leaf-dwelling) crustose lichen in the family Pilocarpaceae. It occurs in Bolivia.
Synarthothelium is a genus of lichen-forming fungi of uncertain familial placement in the order Arthoniales. It has two species of corticolous (bark-dwelling) crustose lichens that occur in tropical regions of the Americas.
Gloeoheppia is a genus of lichen-forming fungi in the family Gloeoheppiaceae. It comprises five species. The genus is distinguished from similar-looking lichens like Heppia by its internal structure, the nature of its photobiont, and details of its reproductive structures.
Joergensenia is a fungal genus in the family Pannariaceae. It comprises a single species, Joergensenia cephalodina, which is a corticolous (bark-dwelling), squamulose lichen found in southern South America.
Megaloblastenia is a genus of crustose lichen-forming fungi in the family Megalosporaceae, comprising three species. Proposed by Dutch lichenologist Harrie Sipman in 1983, the genus is characterised by its thick, ecorticate thallus ranging from pale whitish-grey to yellowish, and its disc-like fruiting bodies (apothecia) that can be biatorine or lecideine. Megaloblastenia lichens form a symbiotic relationship with Dictyochloropsis algae, produce hyaline, bicellular ascospores with polaribilocular structure, and contain chemical compounds such as zeorin, pannarin, or usnic acid. Found in Australasia and South America, these lichens typically grow as epiphytes on trees in moist forests within temperate to tropical oceanic climates.
Paracollema is a small genus of lichen-forming fungi in the family Collemataceae. It comprises two species of jelly lichens, characterised by their small size, gelatinous nature when wet, and distinctive reproductive structures. The genus was proposed in 2013 and later validated in 2017. Paracollema lichens form small, leafy thalli up to 1 cm in diameter, with dark olive green to brownish colouration. They are distinguished from related genera by their very small asci and spores. Both known species are primarily epiphytic and have a limited distribution in southern Europe and northern Africa, typically found in Mediterranean or semi-arid climates.
Tylocliostomum is a fungal genus in the family Ramalinaceae. It comprises the single species Tylocliostomum viridifarinosum.