Psammina

Last updated

Psammina
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: incertae sedis
Order: incertae sedis
Family: incertae sedis
Genus: Psammina
Sacc. & M.Rousseau ex E.Bommer & M.Rousseau (1890)
Type species
Psammina bommerae
Sacc. & M.Rousseau (1890)
Species

See text

Synonyms [1]
  • PycnopsamminaDiederich & Etayo (1995)

Psammina is a fungal genus in the division Ascomycota. The relationship of this taxon to other taxa within the division is unknown ( incertae sedis ), and it has not yet been placed with certainty into any class, order, or family. [2] [3] The genus comprises fungi that inhabit various environments, growing on plants, algae, and lichens. These fungi are notable for their unique reproductive structures, which resemble tiny hands or palms when viewed under a microscope. Psammina species play diverse ecological roles: some form partnerships with algae to create lichens, others grow on existing lichens, and some can cause damage to their host organisms. The genus was first proposed in 1890 and currently includes ten recognised species. While Psammina fungi have been found mainly in Europe, with sightings in countries such as the United Kingdom, the Netherlands, and France, at least one species has been reported in Brazil, suggesting a potentially wider distribution.

Contents

Taxonomy

The genus was published by Elise Caroline Bommer and Marietta Hannon Rousseau in 1890, based on a description provided by Rousseau and Pier Andrea Saccardo. [4]

The taxonomic placement and boundaries of Psammina have been subject to debate. The genus shares similarities with other fungal genera, particularly Cheiromycina and Pycnopsammina. Cheiromycina, like some Psammina species, produces palmate conidia flattened in a single plane, but differs in having conidia that arise from distinctive subglobose, strongly inflated conidiogenous cells. Pycnopsammina was originally described as separate from Psammina due to its reportedly immersed, ostiolate conidiomata. However, a closer examination of the type species, P. lobariae, revealed conidiogenesis details similar to those of Psammina bommeriae. This led Peter Michael Earland-Bennett and David L. Hawksworth (2005) to propose that Pycnopsammina should be treated as a synonym of Psammina. The variation in conidial development among Psammina species has raised questions about whether the genus should be subdivided. [5]

Description

Psammina is a genus of fungi known for its unique reproductive structures. When visible to the naked eye, Psammina appears as small, scattered dark brown to black spots on its host, each spot measuring about 0.1 to 0.2 millimeters across. These spots may look slightly grainy or almost smooth, depending on the species. The main body of the fungus, the mycelium, grows hidden within the tissue of its host. This mycelium consists of brown, branching threads (hyphae) that are slightly swollen at intervals, giving them a beaded appearance. These hyphae are quite thin, measuring only about 2.5 to 3.5  micrometres (μm) in width. [6]

Unlike many fungi, Psammina does not produce enclosed fruiting bodies. Instead, it forms small, cushion-like structures called sporodochia , from which specialised reproductive cells emerge. These reproductive cells, known as conidiophores, stand upright and are unbranched, smooth-walled, and divided into segments. They typically measure 30 to 50 μm in length and about 3 to 3.5 μm in width. At the tips of these conidiophores, Psammina produces its most distinctive feature: unique spores called conidia. These conidia are dry, pale brown, and remarkably complex in structure. They resemble tiny hands or palms, with multiple arm-like projections radiating outward from a central point. The number of these "arms" can vary greatly between species, ranging from fewer than 20 to over 100 per conidium. [6]

The arms of the conidia show considerable variation among different Psammina species. They can be as short as 10 μm or as long as 80 μm, and their width typically ranges from 2 to 4 μm, though some species have arms up to 6 μm wide. The shape of these arms also varies, with some being straight, others curved, some swollen, and others tapering towards the tip. Each arm is divided into segments by cross-walls, with the number of these divisions differing between species. [6]

When gently flattened under a microscope, a mature Psammina conidium can span from about 50 to over 160 μm in diameter, depending on the species. These intricate conidia are key to identifying different species within the genus Psammina, as their specific characteristics vary from one species to another. [6]

The process of conidium formation (conidiogenesis) in Psammina varies among species, which has implications for the genus's taxonomy. In the type species, P. bommeriae, conidia arise as short lateral branches from the conidiophores. However, in other species, such as P. stipitata and P. palmata, conidia are produced from discrete, elongate, vertical conidiogenous cells. The conidiogenous cells in some species are monoblastic (producing a single conidium), integrated (formed from the same hyphae as the vegetative parts), terminal, and often brown and smooth-walled. In P. palmata, for example, these cells can be markedly swollen below and somewhat eccentrically flask-shaped ( ampulliform ), measuring 6–10 by 1.5–2.5 μm. This variation in conidiogenesis among Psammina species has led to discussions about potential subdivision of the genus. [5]

Habitat and distribution

Psammina species exhibit a diverse range of ecological roles and habitats. They can be found in various environments, primarily associated with plants, algae, and lichens. The genus includes species that are saprophytic (living on dead organic matter), lichenised (forming a symbiotic relationship with algae to create lichens), lichenicolous (growing on lichens), or algicolous (growing on algae). [6] Psammina palmata was the first lichen-forming fungus identified in the genus. [5] Many Psammina species show a preference for specific microhabitats. They are often found growing on crusts of green algae and lichens that occur on the dry sides of trees and stones. This particular niche seems to be favoured by several species within the genus, including P. stipitata, P. filamentosa, and P. inflata. These species can be observed as small, often somewhat granular black spots on their host organisms. [6]

The ecological roles of Psammina species can vary. Some, like P. filamentosa, have been observed to be pathogenic, causing bleaching of their host algae or lichens. This suggests that certain Psammina species may play a role in shaping the microbial communities on tree bark and rock surfaces. [6]

In terms of geographical distribution, Psammina species have been reported from several European countries. The genus has been documented in the United Kingdom, the Netherlands, France, Germany, Luxembourg, and Ukraine. However, at least one species, P. tropica, has been reported from Brazil, indicating that the genus may have a wider distribution than currently known. [6]

Species

As of August 2024, Species Fungorum (in the Catalogue of Life) accept 10 species of Psammina: [2]

See also

Related Research Articles

<span class="mw-page-title-main">Ascomycota</span> Division or phylum of fungi

Ascomycota or Endomycopsis, is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus", a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of Ascomycota are asexual and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, brewers' and bakers' yeast, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens such as Cladonia belong to the Ascomycota.

<span class="mw-page-title-main">Pertusariales</span> Order of fungi

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.

<i>Buellia</i> Genus of lichens

Buellia is a genus of mostly lichen-forming fungi in the family Caliciaceae. The fungi are usually part of a crustose lichen. In this case, the lichen species is given the same name as the fungus. But members may also grow as parasites on lichens (lichenicolous). The algae in the lichen is always a member of the genus Trebouxia.

<i>Pseudephebe</i> Genus of fungi

Pseudephebe is a genus of fruticose lichens in the family Parmeliaceae. It contains three species that grow on rocks.

<i>Melanohalea</i> Genus of lichen

Melanohalea is a genus of foliose lichens in the family Parmeliaceae. It contains 30 mostly Northern Hemisphere species that grow on bark or on wood. The genus is characterised by the presence of pseudocyphellae, usually on warts or on the tips of isidia, a non-pored epicortex and a medulla containing depsidones or lacking secondary metabolites. Melanohalea was circumscribed in 2004 as a segregate of the morphologically similar genus Melanelia, which was created in 1978 for certain brown Parmelia species. The methods used to estimate the evolutionary history of Melanohalea suggest that its diversification primarily occurred during the Miocene and Pliocene epochs.

<i>Pilophorus acicularis</i> Species of fungus

Pilophorus acicularis, commonly known as the nail lichen or the devil's matchstick lichen, is a species of matchstick lichen in the family Cladoniaceae.

<span class="mw-page-title-main">Lichenicolous fungus</span> Parasitic fungus that only lives on lichen

A lichenicolous fungus is a member of a specialised group of fungi that live exclusively on lichens as their host organisms. These fungi, comprising over 2,000 known species across 280 genera, exhibit a wide range of ecological strategies, including parasitism, commensalism, and mutualism. They can be found in diverse environments worldwide, from tropical to polar regions, and play important roles in lichen ecology and biodiversity. Lichenicolous fungi are classified into several taxonomic groups, with the majority belonging to the Ascomycota and a smaller portion to the Basidiomycota. Their interactions with host lichens range from mild parasitism to severe pathogenicity, sometimes causing significant damage to lichen communities.

<i>Torula herbarum</i> Species of fungus

Torula herbarum is a darkly-pigmented filamentous fungus in the phylum Ascomycota. It is often included in the unrelated but morphologically similar group of fungi known as sooty molds. It was first described by Persoon in the genus Monilinia based on similarity to the agent of brown rot of stone fruit but later transferred to the genus Torula by Link. Conidia of T. herbarum are dark brown or olivaceous colour and have a distinctive shape and number of cells. T. herbarum produces secondary metabolites with cytotoxic activity towards bacteria and human cancer cells.

Microascus manginii is a filamentous fungal species in the genus Microascus. It produces both sexual (teleomorph) and asexual (anamorph) reproductive stages known as M. manginii and Scopulariopsis candida, respectively. Several synonyms appear in the literature because of taxonomic revisions and re-isolation of the species by different researchers. M. manginii is saprotrophic and commonly inhabits soil, indoor environments and decaying plant material. It is distinguishable from closely related species by its light colored and heart-shaped ascospores used for sexual reproduction. Scopulariopsis candida has been identified as the cause of some invasive infections, often in immunocompromised hosts, but is not considered a common human pathogen. There is concern about amphotericin B resistance in S. candida.

Dacampia is a genus of fungi in the family Dacampiaceae. It contains 15 species. The genus was circumscribed in 1853 by Italian lichenologist Abramo Bartolommeo Massalongo, with Dacampia hookeri assigned as the type species. The genus name honours Italian naturalist Benedetto de Dacampo (1787–1851).

<i>Xenodevriesia</i> Species of ascomycete fungus

Xenodevriesia strelitziicola is a pathogenic ascomycete fungus in the class Dothideomycetes that infects the South African plant Strelitzia. It is the only species of the monotypic genus Xenodevriesia and family Xenodevriesiaceae.

<span class="mw-page-title-main">Glossary of mycology</span>

This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found in glossary of biology and glossary of botany, among others. List of Latin and Greek words commonly used in systematic names and Botanical Latin may also be relevant, although some prefixes and suffixes very common in mycology are repeated here for clarity.

Baidera is a single-species fungal genus in the family Roccellaceae. It contains the species Baidera mauritiana, a corticolous (bark-dwelling), crustose lichen found in Mauritius. Both the genus and species were described as new to science in 2020 by Paul Diederich and Damien Ernst. The genus name honours Cláudia Baider, curator of the Mauritius Herbarium.

Meristacrum is a fungal genus in the monotypic family Meristacraceae, of the order Entomophthorales. They are parasites of soil invertebrates, they typically infect nematodes, and tardigrades.

Conioscypha is a genus of terrestrial and freshwater fungi in the monotypic family Conioscyphaceae and the monotypic order Conioscyphales. They are found on decayed wood, leaves, or bamboo stems. Except for Conioscypha japonica which was isolated from dog skin fragments and hair in 2017.

<i>Protocandelariella</i> Genus of lichens

Protocandelariella is a genus of lichen-forming fungi in the family Candelariaceae. It has two species of squamulose (scaley), corticolous (bark-dwelling) lichens.

Stigmidium cerinae is a species of lichenicolous (lichen-dwelling) fungus in the family Mycosphaerellaceae. It was formally described as a new species in 1994 by mycologists Claude Roux and Dagmar Triebel. The type specimen was collected in Austria from the apothecia of the muscicolous (moss-dwelling) species Caloplaca stillicidiorum. It infects lichens in the genus Caloplaca, and more generally, members of the family Teloschistaceae. Infection by the fungus results in bleaching of the host hymenium.

Racoleus is a genus of two species of lichen-forming fungi of uncertain familial placement in the order Capnodiales. Both species of Racoleus are filamentous lichens with Trentepohlia as the photobiont partner. The lichens form thalli in the form of felt-like, blackish-brown cushions that grow under shaded conditions on siliceous rocks.

Amerosporiopsis phaeographidis is a species of lichenicolous fungus in the subphylum Pezizomycotina. It grows as black spots on the lichen Phaeographis brasiliensis, from which it gets its name. It has only been found in one place in the Fakahatchee Strand Preserve State Park in Florida in the United States. Molecular phylogenetics testing might reveal that this is actually a new genus, but it is morphologically similar to the one other species in Amerosporiopsis, except that it has wider conidia, has no conidiophores, and lives in a different habitat.

Sclerococcum toensbergii is a species of lichenicolous (lichen-dwelling) fungus in the family Sclerococcaceae. It is known from only a couple of collections made in the northwestern United States, and a collection in France. In the United States, it has been recorded on the bark-dwelling lichens Megalaria pulverea and Pertusaria carneopallida, while in France, it was found growing on Caloplaca cerina.

References

  1. ↑ "Synonymy. Current Name: Psammina Sacc. & M. Rousseau ex E. Bommer & M. Rousseau, in Bommer & Rousseau, Bull. Soc. R. Bot. Belg. 29(no. 1): 295 (1890)". Species Fungorum . Retrieved 29 August 2024.
  2. 1 2 "Psammina". Catalogue of Life . Species 2000: Leiden, the Netherlands. Retrieved 29 August 2024.
  3. ↑ Wijayawardene, N.N.; Hyde, K.D.; Dai, D.Q.; Sánchez-García, M.; Goto, B.T.; Saxena, R.K.; et al. (2022). "Outline of Fungi and fungus-like taxa – 2021". Mycosphere. 13 (1): 53–453. doi:10.5943/mycosphere/13/1/2. hdl: 1854/LU-8754813 .
  4. 1 2 Bommer, E.; Rousseau, M. (1890). "Contributions à la Flore Mycologique de Belgique. IV". Bulletin de la Société Royale de Botanique de Belgique (in French). 29 (1): 205–302 [295].
  5. 1 2 3 4 5 Earland-Bennett, P.M.; Hawksworth, D.L. (2005). "The first lichen-forming species of Psammina, P. palmata sp. nov., with notes on the status of Cheiromycina and Pycnopsammina". The Lichenologist. 37 (3): 191–197. doi:10.1017/S0024282905015203.
  6. 1 2 3 4 5 6 7 8 9 van der Kolk, Henk-Jan; Earland-Bennett, Peter M.; Hawksworth, David L. (2020). "A new Psammina species with exceptionally long conidial arms, with a key to the ten known species of the genus". The Lichenologist. 52 (5): 337–343. doi:10.1017/S0024282920000365.
  7. ↑ Lee, S.; Crous, P.W. (2003). "New coelomycetes occurring on Restionaceae" (PDF). Sydowia. 55: 115–128.
  8. 1 2 Earland-Bennett, P.M.; Hawksworth, D.L. (1999). "Observations on the genus Psammina, including the description of two new algicolous and lichenicolous species". The Lichenologist. 31 (6): 579–586. doi:10.1006/lich.1999.0217.
  9. ↑ Sousa Dias, M.R. de; Teixeira, R.S. (1962). "Fungi lusitaniae XVIII". Agronomia Lusitana. 24 (1): 35–38.
  10. ↑ Hawksworth, D.L. (1979). "The lichenicolous Hyphomycetes". Bulletin of the British Museum for Natural History. 6 (3): 183–300 [244].
  11. ↑ Cáceres, M.E.S.; Aptroot, A. (2016). "First inventory of lichens from the Brazilian Amazon in Amapá State". The Bryologist. 119 (3): 250–265. doi:10.1639/0007-2745-119.3.250.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.