| Pleurosticta | |
|---|---|
 | |
| Pleurosticta acetabulum | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Lecanorales |
| Family: | Parmeliaceae |
| Genus: | Pleurosticta Petr. (1931) |
| Type species | |
| Pleurosticta lichenicola Petr. (1931) | |
| Species | |
Pleurosticta is a small genus of foliose lichens belonging to the family Parmeliaceae. It has two species. [1]
The genus was circumscribed by mycologist Franz Petrak in 1931, with Pleurosticta lichenicola assigned as the type species. [2] This is now known as a synonym of P. acetabulum . [3] The genus name fell into disuse when its species were transferred to Melanelia . [4]
In 1980, Theodore Esslinger proposed conserving the name Melanelia for these species. However, H. Thorsten Lumbsch, Hans Kothe, and Jack Elix argued against this in 1988, choosing instead to resurrect Pleurosticta. Their decision was based on detailed morphological, chemical, and geographical studies which demonstrated that P. acetabulum and P. koflerae formed a distinct group warranting recognition at the generic level. The resurrection was supported by several distinctive characteristics that set these species apart from other members of the "brown Parmeliae", including the presence of a pored epicortex, bacilliform to fusiform conidia, a distinctive chemistry characterized by the presence of β-orcinol depsidones, and unique geographical distribution patterns. [4]
Pleurosticta belongs to the parmelioid group of lichens, which are typically leaf-like (foliose) in appearance. The genus is characterized by several distinctive features. Its species have a pored epicortex , meaning the outer protective layer of the lichen has tiny holes in it. They produce spores through specialized structures called conidia, which in this genus are shaped like small rods ( bacilliform ) to spindle-shaped ( fusiform ), measuring between 12–16 μm by 6–11 μm. [4]
The chemistry of Pleurosticta is distinctive among related genera, containing compounds called β-orcinol depsidones. These secondary metabolites are often used to distinguish between different groups of lichens. The genus lacks certain other compounds commonly found in related genera, such as fatty acids. [4]
A key distinguishing feature of Pleurosticta is its temperate distribution pattern, setting it apart from related genera which are found in different climatic regions. For example, some similar-looking genera are primarily found in semi-arid regions or tropical rainforest canopies, while Pleurosticta species are typically found in temperate areas. [4]
The Parmeliaceae is a large and diverse family of Lecanoromycetes. With over 2700 species in 71 genera, it is the largest family of lichen-forming fungi. The most speciose genera in the family are the well-known groups: Xanthoparmelia, Usnea, Parmotrema, and Hypotrachyna.
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.
Melanelixia is a genus of foliose lichens in the family Parmeliaceae. It contains 15 Northern Hemisphere species that grow on bark or on wood. The genus is characterized by a pored or fenestrate epicortex, and the production of lecanoric acid as the primary chemical constituent of the medulla. Melanelixia was circumscribed in 2004 as a segregate of the related genus Melanelia.
Parmotrema is a genus of lichen belonging to the family Parmeliaceae. It is a large genus, containing an estimated 300 species, with a centre of diversity in subtropical regions of South America and the Pacific Islands.
Punctelia is a genus of foliose lichens belonging to the large family Parmeliaceae. The genus, which contains about 50 species, was segregated from genus Parmelia in 1982. Characteristics that define Punctelia include the presence of hook-like to thread-like conidia, simple rhizines, and point-like pseudocyphellae. It is this last feature that is alluded to in the vernacular names speckled shield lichens or speckleback lichens.
Relicina is a genus of foliose lichens belonging to the large family Parmeliaceae. It contains 60 species.
Xanthoparmelia is a genus of foliose lichens in the family Parmeliaceae. This genus of lichen is commonly found in the United States, South America, southern Africa, Europe, Australia, and New Zealand.
Psiloparmelia is a genus of lichen belonging to the family Parmeliaceae. It contains 13 Southern Hemisphere species, most of which are found growing on rocks at high elevations in South America. There are several characteristic features of the genus that are used to distinguish it from the morphologically similar genera, such as Arctoparmelia, Flavoparmelia, and Xanthoparmelia. These include a dark, velvety lower thallus surface that usually lacks rhizines, a negative test for lichenan, and a high concentration of usnic acid and atranorin in the cortex.
Imshaugia is a genus of seven species of foliose lichens in the family Parmeliaceae. They are commonly known as starburst lichens.
Allantoparmelia is a genus of lichenised fungi in the large family Parmeliaceae. It is a genus of only three currently accepted species. All three Allantoparmelia lichens have a foliose growth form. They appear to be a very slow growing group of lichens, with a mean annual thallus diameter increase of only 0.23–0.35 mm per year.
Pseudoparmelia is a genus of lichen-forming fungi in the family Parmeliaceae. The genus has a pantropical distribution.
Alectoria is a genus of fruticose lichens belonging to the family Parmeliaceae.
Remototrachyna is a genus of foliose lichens in the large family Parmeliaceae. It was separated from the genus Hypotrachyna based on the structure of the excipulum and genetic differences.
Emodomelanelia is a lichen genus in the family Parmeliaceae. It is monotypic, containing the single foliose Himalayan species Emodomelanelia masonii.
Austromelanelixia is a genus of five species of foliose lichens in the family Parmeliaceae. All species are found in the Southern Hemisphere.
Neoprotoparmelia is a genus of crustose lichens that was created in 2018. It contains 24 tropical and subtropical species that mostly grow on bark. Neoprotoparmelia is in the subfamily Protoparmelioideae of the family Parmeliaceae, along with the morphologically similar genera Protoparmelia and Maronina.
John Alan (Jack) Elix emeritus professor in chemistry at the Australian National University, is an organic chemist who has contributed in many fields: lichenology, lichen chemotaxonomy, plant physiology and biodiversity and natural product chemistry. He has authored 2282 species names, and 67 genera in the field of mycology. Elix edited the exsiccata series Lichenes Australasici exsiccati.
Pleurosticta acetabulum is a species of foliose lichen in the family Parmeliaceae. It is common and widespread throughout Europe, where it grows on tree bark. It has also been recorded in Algeria.
Pleurosticta koflerae is a species of foliose lichen in the family Parmeliaceae. It is a member of the group of species informally known as the "brown Parmeliae". The lichen was first formally described as Parmelia koflerae by lichenologists Georges Clauzade and Josef Poelt in 1961. Theodore Esslinger transferred it to the genus Melanelia in 1978 when he reorganized the classification of the brown Parmeliae, a continuation of his research on the group published the year before. It was finally transferred to the newly resurrected genus Pleurosticta in 1988 by H. Thorsten Lumbsch and John A. Elix.
Flavoparmelia virensica is a species of corticolous (bark-dwelling), foliose lichen found in Western Australia, newly described in 2010. This species, belonging to the large family Parmeliaceae, is similar in appearance to Flavoparmelia rutidota and F. caperatula, but can be distinguished by its spindle-shaped conidia and significant quantities of virensic acid. The lichen grows on dead and burnt wood as well as the bark of trees from the genera Allocasuarina, Acacia, and Hakea.