| Pyxine cocoes | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Caliciales |
| Family: | Caliciaceae |
| Genus: | Pyxine |
| Species: | P. cocoes |
| Binomial name | |
| Pyxine cocoes | |
| Synonyms [1] | |
Pyxine cocoes, the buttoned rosette lichen, [2] is a widely distributed species of foliose lichen in the family Caliciaceae.
It was first described as a new species by Swedish botanist Olof Swartz in 1788. He called it Lichen cocoës, [3] following the lead of Carl Linnaeus who, in his influential 1753 work Species Plantarum , placed all lichens in the eponymous genus Lichen. Finnish lichenologist William Nylander transferred it to the genus Pyxine in 1853. [4] A common name used in North America is the "buttoned rosette lichen". [2]
Pyxine cocoes has a pale grayish-green thallus comprising radiating lobes that are typically less than 1 mm wide. These lobes are closely attached to the surface of the substrate, have granular soredia that protrude through the cortex in irregularly shaped regions called soralia. The medulla is white, while the apothecia are black with black margins in mature specimens. [2] They are 1–5 mm wide, flat, and disc-shaped. [5] The tissue making up the base of the apothecia is brownish red. [2] Ascospores measure 15–22 by 6–8 μm. [5] The lichen contains lichexanthone, a xanthone compound that is found in about 20 Pyxine species. [6]
Pyxine cocoes grows on bark and rocks. [5] The lichen has been reported from Asia (Japan and the Philippines), East Africa, North America, Central America, and South America, Hawaii, and Australia. In Australia, it is present only in coastal locations that are seasonally humid, and both wet and warm. In this continent, it is common on tree trunks growing on coral cays; these trunks are often used as bird perches, which accumulate bird droppings. The lichenologist Roderick W. Rogers suggests that the lichen could be nitrophilic, which would explain this growth habitat, as well as its tendency to prefer habitats that are at least partially urbanized. [5] In North America, it distribution extends as far north to Florida in the United States. [2]
The African species Pyxine katendei is somewhat similar in appearance to Pyxine cocoes, but it has only laminal (not marginal) soralia. [5]
Studies conducted in India suggest that Pyxine cocoes is a candidate for biomonitoring of local air pollution. [7] It bioaccumulates toxic heavy metals that it acquires from the air and retains the pollutants in the thallus, which can then be sampled and assayed to determine their concentration. [8] [9] [10]
Pyxine cocoes is used in Papua New Guinea as a component of a traditional medicine-based remedy for inflammatory conditions. In a chemical analysis of the lichen, the triterpene compound 6,22-hopanediol was identified. [11] This compound, commonly known as zeorin, is a hopanoid with potent inhibitory activity against the enzyme protein tyrosine phosphatase. [12]
Parmelia is a genus of medium to large foliose lichens. It has a global distribution, extending from the Arctic to the Antarctic continent but concentrated in temperate regions. There are about 40 species in Parmelia. In recent decades, the once large genus Parmelia has been divided into a number of smaller genera according to thallus morphology and phylogenetic relatedness.
Phyllopsora is a genus of lichen-forming fungi in the family Ramalinaceae. It was circumscribed by Swiss botanist Johannes Müller Argoviensis in 1894, with Phyllopsora breviuscula assigned as the type species.
Pyxine is a genus of foliose lichens in the family Caliciaceae. The genus has a widespread distribution in tropical regions.
Hypogymnia is a genus of foliose lichens in the family Parmeliaceae. They are commonly known as tube lichens, bone lichens, or pillow lichens. Most species lack rhizines that are otherwise common in members of the Parmeliaceae, and have swollen lobes that are usually hollow. Other common characteristics are relatively small spores and the presence of physodic acid and related lichen products. The lichens usually grow on the bark and wood of coniferous trees.
Myelochroa is a genus of foliose lichens in the family Parmeliaceae. They are commonly known as axil-bristle lichens. It was created in 1987 to contain species formerly placed in genus Parmelina that had a yellow-orange medulla due to the presence of secalonic acids. Characteristics of the genus include tightly attached thalli with narrow lobes, cilia on the axils, and a rhizinate black lower surface. Chemical characteristics are the production of zeorin and related triterpenoids in the medulla. Myelochroa contains about 30 species, most of which grow on bark. The genus has centres of distribution in Asia and North America.
Lepraria is a genus of leprose crustose lichens that grows on its substrate like patches of granular, caked up, mealy dust grains. Members of the genus are commonly called dust lichens. The main vegetative body (thallus) is made of patches of soredia. There are no known mechanisms for sexual reproduction, yet members of the genus continue to speciate. Some species can form marginal lobes and appear squamulose. Because of the morphological simplicity of the thallus and the absence of sexual structures, the composition of lichen products are important characters to distinguish between similar species in Lepraria.
The Caliciaceae are a family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. Although the family has had its classification changed several times throughout its taxonomic history, the use of modern molecular phylogenetic methods have helped to establish its current placement in the order Caliciales. Caliciaceae contains 39 genera and about 670 species. The largest genus is Buellia, with around 300 species; there are more than a dozen genera that contain only a single species.
Dalip Kumar Upreti is an Indian lichenologist. He served as Director and Chief Scientist at CSIR-National Botanical Research Institute, Lucknow during 1988 to 2017. Also he served as Head of Lichenology and herbarium division. Presently he is serving as CSIR-Emeritus Scientist in the same division.
Pyxine sorediata, commonly known as mustard lichen, is a widely distributed species of foliose lichen in the family Caliciaceae. It has a subtropical to warm temperate distribution, and grows on bark, rocks, and moss as substrates. Pyxine sorediata has been reported from regions of North America, Europe, Africa, Asia, and Australasia.
Melanohalea subolivacea, commonly known as the brown-eyed camouflage lichen, is a species of foliose lichen in the family Parmeliaceae.
Pyxine subcinerea is a species of foliose lichen in the family Caliciaceae. It has a pantropical distribution, and typically grows on bark, but less commonly on rocks. The lichen is characterised by its yellow medulla, soralia on the margins on the lobes that make up the thallus, and the presence of the chemical lichexanthone in the cortex.
Punctelia hypoleucites, commonly known as the southwestern speckled shield lichen, is a species of foliose (leafy) lichen in the family Parmeliaceae. First formally described by Finnish botanist William Nylander as a species of Parmelia, it was transferred to the genus Punctelia in 1982. The lichen is found in Africa, North America, and South America, where it grows on the bark of both hardwood and coniferous trees. Its greenish-grey thallus is covered with tiny white pseudocyphellae – minute holes in the thallus surface that facilitate gas exchange. Some macroscopic features that help distinguish this species from other related members of the genus include the presence and the structure of the apothecia, the absence of asexual surface propagules, and the light brown color of the thallus undersurface. Chemically, the presence of lecanoric acid in the medulla and atranorin in the cortex help distinguish it from lookalikes.
Parmelia fraudans is a species of foliose lichen in the family Parmeliaceae. It is found in Europe and North America, where it grows on rocks.
Pyxine albovirens is a species of foliose lichen in the family Caliciaceae that is found in North America and South America. It was first formally described as a species of Lecidea in 1818 by German botanist Georg Friedrich Wilhelm Meyer. André Aptroot transferred it to the genus Pyxine in 1987.
Pyxine pustulata is a species of corticolous (bark-dwelling), foliose lichen in the family Caliciaceae. Found in Botucatu, Brazil, it was formally described as a new species in 2014 by lichenologists André Aptroot and Patrícia Jungbluth. The type specimen was collected by the authors from the botanical garden on the campus of Botucatu at an altitude of 850 m (2,790 ft).
Pyxine lyei is a species of saxicolous (rock-dwelling), foliose lichen in the family Caliciaceae. Found in East Africa, it was scientifically described as a new species in 1975 by lichenologists Dougal Swinscow and Hildur Krog. The lichen has a whitish thallus that is tightly appressed to its substrate. The lobes comprising the thallus are flat, and have faint pseudocyphellae as well as patches of pruina. The thallus underside is black; the internal medulla is white. The lichen contains triterpenoid compounds as well as lichexanthone; the latter substance causes the lichen to fluoresce when lit with a long-wavelength UV light.
Pyxine lilacina is a rare species of saxicolous (rock-dwelling), foliose lichen in the family Caliciaceae. Found in East Africa, it was scientifically described as a new species in 1975 by lichenologists Dougal Swinscow and Hildur Krog. The lichen has a brownish-grey to lilac-grey thallus that is tightly appressed to its substrate. The lobes comprising the thallus are flat, and have pseudocyphellae as well as patches of pruina. The thallus underside is black; the internal medulla is white. The lichen contains triterpenoid compounds as well as lichexanthone; the latter substance causes the lichen to fluoresce when lit with a long-wavelength UV light.
Caloplaca cupulifera is a widely distributed species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. It has a chrome-yellow thallus with bright yellow cup-shaped soredia. Although originally described as a new species in 1915 and placed in the large genus Caloplaca in 1931, modern molecular phylogenetics suggests that its classification requires an update.
Opegrapha physciaria is a species of lichenicolous (lichen-dwelling) fungus in the family Opegraphaceae. It was first formally described as a new species in 1897 by Finnish lichenologist William Nylander, who placed it in the genus Lecidea. David Hawksworth and Brian J. Coppins transferred it to the genus Opegrapha in 1992.
Pyxine petricola is a species of saxicolous (rock-dwelling), foliose lichen in the family Caliciaceae. The distribution of the lichen includes Australia, East Africa, North and Central America, and the Philippines.