''Arctoparmelia separata'', commonly known as the rippled ring lichen, is a species of foliose, ring lichen in the family Parmeliaceae with a roughly circumpolar distribution.

Taxonomy

The lichen was first described scientifically by

Theodor Magnus Fries Theodor "Thore" Magnus Fries (28 October 1832 – 29 March 1913), was a Swedish botanist, lichenologist, and Arctic explorer. He was the son of the mycologist Elias Fries. Following in his father's footsteps, Fries studied botany, obtaining his ...

in 1879 as a species of '' Parmelia''.

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

transferred it to ''

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

'' in 1974. In 1986, Hale segregated five ''Xanthoparmelia'' species to the newly-created genus '' Arctoparmelia'' in 1986. This group of species, including ''X. separata'', is characterized by the velvety, ivory-white to purplish colour of the lower surface of the thallus, the presence of alectoronic acid, and a geographical range restricted to arctic or

boreal Boreal may refer to: Climatology and geography *Boreal (age), the first climatic phase of the Blytt-Sernander sequence of northern Europe, during the Holocene epoch *Boreal climate, a climate characterized by long winters and short, cool to mild ...

locations. ''Arctoparmelia separata'' is commonly known as the rippled ring lichen.

Description

''Arctoparmelia separata'' resembles the more common '' Arctoparmelia centrifuga'', but is distinguished from that species by the dull mouse-grey colour of its lower surface, and its thicker and more rigid thallus, and its long lobes that are

divaricate Divaricate means branching, or having separation or a degree of separation. The angle between branches is wide. In botany In botany, the term is often used to describe the branching pattern of plants. Plants are said to be divaricating when the ...

ly branched. The lichen has an incompletely circumpolar distribution. It has been recorded from northern North America, Greenland, and Japan, and Siberia west to

Novaya Zemlya Novaya Zemlya (, also , ; rus, Но́вая Земля́, p=ˈnovəjə zʲɪmˈlʲa, ) is an archipelago in northern Russia. It is situated in the Arctic Ocean, in the extreme northeast of Europe, with Cape Flissingsky, on the northern island, ...

. It has not been recorded in continental Europe.

References

{{Taxonbar, from=Q10417298 Parmeliaceae Lichen species Lichens described in 1879 Lichens of Asia Lichens of North America Taxa named by Theodor Magnus Fries Lichens of the Arctic