''Punctelia diffractaica'' is a species of foliose lichen in the family Parmeliaceae. It is found in Peru.

Taxonomy

The lichen was described as a species new to science by Japanese lichenologist

Syo Kurokawa Kashiwadani. was a noted Japanese lichenologist and 1994 recipient of the Acharius Medal. He studied under Mason HaleDePriest. and Yasuhiko Asahina. Eponyms Several lichen species have been named to honour Kurokawa. These eponyms include: '' Usn ...

in 1999. The

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

was collected by colleague Hiroyuki Kashiwadani in the

Saylla District Saylla District is one of eight districts of the province Cusco in Peru. Instituto Nacional de Estadística e Informática. Banco de Información Distrital''. Retrieved April 11, 2008. See also * Pachatusan * Waqutu Waqutu (Quechua for the na ...

( Cuzco Province), where it was found in a pasture on the side of a road, growing on a

calcareous rock Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adje ...

at an altitude of about . It is named for its uncommon metabolite,

diffractaic acid Diffractaic acid is a β-orcinol depside with the molecular formula C20H22O7, which is produced by lichens. Diffractaic acid has cytotoxic, cytogenetic, oxidative, analgesic An analgesic drug, also called simply an analgesic (American Eng ...

Description

The lichen has a foliose (leafy) thallus that is greenish-gray in colour, with a tight attachment to its

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (locomotion), the surface over which an organism lo ...

. It has a more or less rough, leathery texture, reaching dimensions of in diameter, comprising irregular lobes that are wide. Like all species of ''

Punctelia ''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 ...

'', ''P. diffractaica'' has minute pores –

pseudocyphella Pseudocyphellae (singular ''pseudocyphella'') are structures in lichens that appear as tiny pores on the outer surface (the cortex of the lichen. They are caused when there is a break in the cortex of the lichen, and the medullary hyphae extend t ...

e – that help facilitate gas exchange. The thallus surface features isidia that originate either from the pseudocyphellae, or directly from the surface. The medulla is white, while the underside of the thallus is black, with sparse, short black rhizines less than 1 mm long. In the type specimen, most of the apothecia (sexual reproductive organs) were juvenile, measuring less than 2 mm in diameter, and not reported in the description. ''Punctelia diffractaica'' contains atranorin and diffractaic acid is its main secondary chemicals. The latter chemical is rare in the family Parmeliaceae, and not otherwise known to occur in genus ''

''. It is the presence of this chemical that allows this species to be distinguished from the morphologically similar species ''

Punctelia punctilla ''Punctelia punctilla'' is a species of foliose lichen in the family Parmeliaceae. It is found in Africa, South America, and North America, where it grows on bark and on rocks. The main characteristics that distinguish ''Punctelia punctilla'' ...

'', which also occurs in South America. Diffractaic acid is in the class of compounds called

depside A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester bond. Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, L ...

s, and has been scientifically investigated for biological properties such as

antioxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...

, antiulcerogenic and gastroprotective effects.

References

{{Taxonbar, from=Q10646743 diffractaica Lichen species Lichens described in 1999 Taxa named by Syo Kurokawa Lichens of Peru