''Hypotrachyna osseoalba'', commonly known as the grainy loop lichen, is a species of

foliose lichen A foliose lichen is a lichen with flat, leaf-like , which are generally not firmly bonded to the substrate on which it grows. It is one of the three most common growth forms of lichens. It typically has distinct upper and lower surfaces, each o ...

in the family

Parmeliaceae 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'' ( 82 ...

. It is widely distributed in

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

and

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

areas of the world. Characteristic features of the lichen include the pustules in its

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

, the somewhat linear shape of the lobes comprising the

thallus Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...

, and the branched

rhizine In lichens, rhizines are multicellular root-like structures arising mainly from the lower surface. A lichen with rhizines is termed rhizinate, while a lichen lacking rhizines is termed erhizinate. Rhizines serve only to anchor the lichen to their s ...

s (holdfasts on the thallus underside).

Taxonomy

It was first

scientifically described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it diffe ...

by Finnish lichenologist

Edvard Vainio Edvard August Vainio (born Edvard Lang; 5 August 185314 May 1929) was a Finnish lichenologist. His early works on the lichens of Lapland, his three-volume monograph on the lichen genus ''Cladonia'', and, in particular, his study of the class ...

in 1921, as ''Parmelia osseoalba''. Yun Sil Park and

Mason Hale Mason Ellsworth Hale, Jr. (September 23, 1929 – April 23, 1990) was one of the most prolific American lichenologists of the 20th century. Many of his scholarly articles focused on the taxonomy of the family Parmeliaceae. Hale was one of the fi ...

transferred it to the genus ''

Hypotrachyna ''Hypotrachyna'' is a genus of lichenized fungi within the family Parmeliaceae. According to the ''Dictionary of the Fungi'' (10th edition, 2008), the widespread genus contains about 198 species. ''Hypotrachyna'' was circumscribed by American lic ...

'' in 1989. The taxon ''Parmelia formosana'', described by

Alexander Zahlbruckner Alexander Zahlbruckner (31 May 1860, Svätý Jur – 1938, Vienna) was an Austrian- Hungarian botanist who specialized in the study of lichens. Johann Babtist Zahlbruckner, an earlier Austrian botanist, was his grandfather. From 1878 to 1883 ...

in 1934, later became ''Hypotrachyna formosana'' after Hale transferred it to ''Hypotrachyna'' in 1975. When Hale was later working on a

monograph A monograph is generally a long-form work on one (usually scholarly) subject, or one aspect of a subject, typically created by a single author or artist (or, sometimes, by two or more authors). Traditionally it is in written form and published a ...

of genus ''

Xanthoparmelia ''Xanthoparmelia'' (commonly known as green rock shields or rock-shield lichens) is a genus of foliose lichens in the family Parmeliaceae.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, This genus of lichen i ...

'', he studied 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. * ...

material of Vainio's ''Parmelia osseoalba'', and determined that it was identical both chemically and morphologically to ''Hypotrachyna formosana''. Because of this, the name used by Zahlbruckner became a later

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of Vainio's name. In North America, ''Hypotrachyna osseoalba'' is commonly known as the "grainy loop lichen".

Chemistry

Several secondary compounds are known to occur in ''Hypotrachyna osseoalba'', including colensoinic acid, norcolensoic acid, physodic acid, lividic acid, 4-''O''-demethylphysodic acid, oxyphysodic acid, and

lichexanthone Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of foliose lichen, leafy lichen in the 1940s. The compound is known ...

Distribution

''Hypotrachyna osseoalba'' occurs in

and

areas of Asia (South Korea, Japan, Taiwan, and Thailand) Australia, Africa, Central America, South America, and the

eastern United States The Eastern United States, often abbreviated as simply the East, is a macroregion of the United States located to the east of the Mississippi River. It includes 17–26 states and Washington, D.C., the national capital. As of 2011, the Eastern ...

References

{{Taxonbar, from=Q15015267 osseoalba Lichen species Lichens described in 1921 Lichens of Asia Lichens of Africa Lichens of Australia Lichens of Central America Lichens of North America Lichens of South America Taxa named by Edvard August Vainio