''Oreojuncus trifidus'' is a species of rush known by the common names highland rush and three-leaved rush. It is native to the Northern Hemisphere, where it is an arctic/montane species with an amphi-atlantic distribution.

Description

''Oreojuncus trifidus'' is a perennial herb with tufted stems up to 40 centimeters long, growing erect or drooping. There are a few grasslike leaf blades measuring up to 12 centimeters long. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

holds one to four flowers with brown

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s and six stamens. The fruit is a capsule a few millimeters long.''Juncus trifidus''.
Flora of North America. The plant reproduces sexually with its flowering structures and

vegetatively Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is any form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or spec ...

via its rhizome, when it may form colonies.

Habitat

This species grows in a number of habitat types, especially in

alpine Alpine may refer to any mountainous region. It may also refer to: Places Europe * Alps, a European mountain range ** Alpine states, which overlap with the European range Australia * Alpine, New South Wales, a Northern Village * Alpine National Pa ...

environments. It can be found in talus, on cliffs and ledges,

fellfield A fellfield or fell field comprises the environment of a slope, usually alpine or tundra, where the dynamics of frost (freeze and thaw cycles) and of wind give rise to characteristic plant forms in scree interstices. Soil dynamics The freeze-thaw ...

tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...

, and meadows. It grows in a wide variety of

heath A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a cooler a ...

ecosystems. The soils may be dry to moist, calcareous, and acidic.Schori, M
Conservation Assessment for Highland Rush (''Juncus trifidus'') L.
USDA Forest Service, Eastern Region. May 6, 2004. They may be gravelly, sandy, and rich in iron. The plant is known as a

pioneer Pioneer commonly refers to a settler who migrates to previously uninhabited or sparsely inhabited land. In the United States pioneer commonly refers to an American pioneer, a person in American history who migrated west to join in settling and de ...

on ski slopes and roadsides. It may grow alongside many types of mosses and lichens.

Distribution

''Oreojuncus trifidus'' is an amphi-atlantic plant, native to northern and eastern Canada, including the

Canadian Arctic Archipelago The Arctic Archipelago, also known as the Canadian Arctic Archipelago, is an archipelago lying to the north of the Canadian continental mainland, excluding Greenland (an autonomous territory of Denmark). Situated in the northern extremity of ...

and other low

Arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, N ...

regions, the northeastern United States,

Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland i ...

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...

, northern

Britain Britain most often refers to: * The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands * Great Britain, the largest island in the United King ...

, and northern Asia.Aiken, S.G., et al. 2007
Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval.
NRC Research Press, National Research Council of Canada, Ottawa. It also occurs in the high mountains of southern Europe. While not rare in general, the plant faces threats in some locations. Some populations in the

Adirondacks The Adirondack Mountains (; a-də-RÄN-dak) form a massif in northeastern New York with boundaries that correspond roughly to those of Adirondack Park. They cover about 5,000 square miles (13,000 km2). The mountains form a roughly circular d ...

are harmed by trampling by hikers.''Juncus trifidus''.
New York Natural Heritage Program. Rush habitat on

Camel's Hump Camel's Hump (alternatively Camels Hump) is a mountain in the Green Mountains in the U.S. state of Vermont. The north slope of the mountain borders the Winooski River, which has carved through the Green Mountains over eons. At , it is tied (with ...

and

Mount Marcy Mount Marcy (Mohawk: ''Tewawe’éstha'') is the highest point in New York, with an elevation of . It is located in the Town of Keene in Essex County. The mountain is in the heart of the Adirondack High Peaks region of the High Peaks Wildern ...

also suffers from trampling disturbance. Rush-dominated heath in the

Cairngorms The Cairngorms ( gd, Am Monadh Ruadh) are a mountain range in the eastern Highlands of Scotland closely associated with the mountain Cairn Gorm. The Cairngorms became part of Scotland's second national park (the Cairngorms National Park) on 1 S ...

is also potentially threatened by trampling.Pryor, P. J. 1985
The effects of disturbance on open ''Juncus trifidus'' health in the Cairngorm mountains, Scotland. In: The ecological impacts of outdoor recreation on mountain areas in Europe and North America.
RERG Report, Recreation Ecology Research Group, UK. No. 9 53-62.

References

{{Taxonbar, from1=Q50347044, from2=Q159896 Juncaceae Flora of North America Plants described in 1753 Taxa named by Carl Linnaeus