Oceanoplaca
From Wikipedia, the free encyclopedia
| Oceanoplaca | |
|---|---|
 | |
| Oceanoplaca isidiosa; scale bar: 2 mm | |
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Teloschistales |
| Family: | Teloschistaceae |
| Genus: | Oceanoplaca Arup, Søchting & Bungartz (2020) |
| Type species | |
| Oceanoplaca isidiosa (Vain.) Bungartz, Søchting & Arup (2020) | |
| Species | |
|
O. caesioisidiata | |
Oceanoplaca is a fungal genus in the family Teloschistaceae. It comprises six species of crustose lichens that grow primarily on rocks in coastal and arid environments, particularly in the Galápagos Islands, Cape Verde, and parts of Central and North America. The genus was established in 2020 based on molecular and morphological studies, with some species producing the rare pigment isidiosin while others lack it. Many species reproduce asexually through small, breakaway outgrowths (isidia) rather than forming the more typical disk-shaped fruiting bodies.
Oceanoplaca was established in 2020 by Ulf Arup, Ulrik Søchting, and Frank Bungartz during a molecular and morphological revision of Teloschistaceae from the Galápagos Islands. The type species is Oceanoplaca isidiosa. In phylogenetic analyses, Oceanoplaca forms a distinct lineage within the subfamily Caloplacoideae and is recovered as a close relative (sister group) of the genus Phaeoplaca,[1] (now Obscuroplaca).[2]
The generic name combines "-placa" (a nod to the broad traditional genus Caloplaca, where several species were previously placed) with "oceano-", referring to the frequent association of the known species with coastal environments. The genus includes species with different chemistry: some produce the rare anthraquinone pigment isidiosin (for example, O. isidiosa and O. chemoisidiosa), while others lack it (for example O. sideritoides).[1]
Sergey Kondratyuk and colleagues (2022) argued that Oceanoplaca does not warrant recognition as a separate genus and should be treated as a synonym of Loekoeslaszloa, based on their multi-locus phylogenetic analyses. They accordingly proposed transferring species previously placed in Oceanoplaca into Loekoeslaszloa (including L. isidiosa, L. chemoisidiosa, and L. sideritoides).[3][4] However, this proposed synonymy has not been adopted by the main fungal nomenclatural repositories: as of January 2026[update], both Index Fungorum and MycoBank still list Oceanoplaca as a distinct genus rather than treating it under Loekoeslaszloa.[5][6]
Description
Species of Oceanoplaca are crustose lichens, forming a thin to thick crust (the thallus) closely attached to the substrate. The thallus can range from a granular, broken-up crust to more continuous patches with small, scale-like units, and in some species it develops a more rosette-like form with radiating marginal lobes (placodioid growth). Many species reproduce asexually with isidia—tiny outgrowths that break off and help the lichen spread.[1]
When present, the sexual fruiting bodies are disk-shaped apothecia. Depending on the species, apothecia may have different kinds of margins (often described in lichenology as lecanorine, biatorine, or zeorine). Microscopically, the asci are club-shaped and typically contain eight spores. The ascospores are polarilocular (two-celled with a conspicuous, thickened septum), a common spore type in Teloschistaceae.[1]
Chemically, Oceanoplaca species may contain anthraquinone pigments in the thallus and/or apothecia; in some species the uncommon anthraquinone isidiosin occurs in the apothecia and may also occur in the thallus. Differences in pigment chemistry help separate otherwise similar-looking species within the genus.[1]