Artemisia tridentata
Encyclopedia
Artemisia tridentata (also called sagebrush/common sagebrush, big sagebrush, blue/black sagebrush or mountain sagebrush) is a shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

 or small tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

 from the family Asteraceae
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...

. Some botanists treat it in the segregate
Segregate (taxonomy)
In taxonomy, a segregate, or a segregate taxon is created when a taxon is split off, from another taxon. This other taxon will be better known, usually bigger, and will continue to exist, even after the segregate taxon has been split off...

 genus Seriphidium, as S. tridentatum (Nutt.) W. A. Weber, but this is not widely followed. The vernacular name "sagebrush"
Sagebrush (plant)
Sagebrush is the common name for Artemisia tridentata and a number of other species of shrubby plants in the genus Artemisia, native to the North American west and other parts of the world. It is sometimes confused with sage plants ....

 is also used for several related members of the genus Artemisia
Artemisia (plant)
Artemisia is a large, diverse genus of plants with between 200 to 400 species belonging to the daisy family Asteraceae. It comprises hardy herbs and shrubs known for their volatile oils. They grow in temperate climates of the Northern Hemisphere and Southern Hemisphere, usually in dry or semi-dry...

, such as California Sagebrush
Artemisia californica
Artemisia californica, also known as California sagebrush, of the Asteraceae family, is a shrub that grows in coastal sage scrub, coastal strand, chaparral, and dry foothill communities, from sea level to 800 m...

 (Artemisia californica).

Description and habitat

Sagebrush is a coarse, hardy silvery-grey bush with yellow flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s and grows in arid sections of the western United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and Western Canada
Western Canada
Western Canada, also referred to as the Western provinces and commonly as the West, is a region of Canada that includes the four provinces west of the province of Ontario.- Provinces :...

. It is the primary vegetation across vast areas of the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...

 desert. Along rivers or in other relatively wet areas, sagebrush can grow as tall as 3 m (10 feet), but is more typically 1–2 m tall.

Sagebrush has a strong pungent fragrance, especially when wet, which is not unlike common sage
Common sage
Salvia officinalis is a small, perennial, evergreen subshrub, with woody stems, grayish leaves, and blue to purplish flowers. It is a member of the family Lamiaceae and is native to the Mediterranean region, though it has naturalized in many places throughout the world...

. It is, however, unrelated to common sage and has a bitter taste. It is thought that this odor serves to discourage browsing.

Sagebrush leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 are wedge-shaped 1–4 cm long and 0.3–1 cm broad, and are attached to the branch by the narrow end. The outer and wider end is generally divided into three lobes (although leaves with two or four lobes are not uncommon), hence the scientific name tridentata. The leaves are covered with fine silvery hairs, which are thought to keep the leaf cool and minimize water loss. Most of the leaves are carried year-round, as sagebrush tends to grow in areas where winter precipitation is greater than summer precipitation.

Sagebrush flowers in the late summer or early fall. The flowers are yellow and are carried in long, slender clusters.

Sagebrush is not fire-tolerant and relies on wind-blown seeds from outside the burned area for re-establishment. This is in contrast to many of the other plants which share its habitat, such as Rabbitbrush
Rabbitbrush
Rabbitbrush is a common name for plants in two related genera of the family Asteraceae:* Chrysothamnus — most species, including Green Rabbitbrush* Ericameria — Gray and Parry's Rabbitbrush...

, Ephedra
Ephedra (genus)
Ephedra is a genus of gymnosperm shrubs, the only genus in its family, Ephedraceae, and order, Ephedrales. Ephedra grows in dry climates over wide areas of the northern hemisphere, including southwestern North America, Europe, north Africa, and southwest and central Asia, and, in the southern...

 and bunchgrasses, which can root-sprout after a fire. Cheatgrass has invaded much of the sagebrush habitat, and if left unchecked could possibly create a fire cycle that is too frequent to allow sagebrush to re-establish itself.

In the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...

, sagebrush is the dominant plant life in the Upper Sonoran and Boreal life zone
Life zone
The Life Zone concept was developed by C. Hart Merriam in 1889 as a means of describing areas with similar plant and animal communities. Merriam observed that the changes in these communities with an increase in latitude at a constant elevation are similar to the changes seen with an increase in...

s, and is the primary understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...

 species in the Transitional zone between them. Prior to heavy grazing by cattle and sheep of these areas, sagebrush is thought to have been less dominant, and perennial
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

 grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...

es more common. In the Lower Sonoran life zone, sagebrush is generally replaced by shadscale or greasewood
Greasewood
Greasewood, Sarcobatus, is a genus of one or two species of flowering plants. Traditionally it has been treated in the family Chenopodiaceae, but the APG II system, of 2003, places it in the family Sarcobataceae....



Sagebrush is the state flower of Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...

.

Taxonomy

There are four accepted subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

:
  • Artemisia tridentata subsp. parishii (A. Gray) H. M. Hall & Clem. (Syn. A. parishii A. Gray, A. tridentata var. parishii (A. Gray) Jeps.)
  • Artemisia tridentata subsp. tridentata
  • Artemisia tridentata subsp. vaseyana (Rydb.) Beetle (Syn. A. tridentata var. vaseyana (Rydb.) B. Boivin, A. vaseyana Rydb.)
  • Artemisia tridentata subsp. wyomingensis Beetle & A. L. Young (Syn. A. tridentata var. wyomingensis (Beetle & A. L. Young) S. L. Welsh)


Other subspecies found in literature but not accepted by the Integrated Taxonomic Information System
Integrated Taxonomic Information System
The Integrated Taxonomic Information System is a partnership designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagency group within the U.S...

 include:
  • Artemisia tridentata subsp. xericensis Winward ex Rosentreter & R. G. Kelsey
  • Artemisia tridentata subsp. cana USFS ("Evolution and Taxonomy of Sagebrush")


Use and toxicity

The plant is highly allergenic to humans, and can cause dermatitis
Dermatitis
-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...

 if applied to the skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...

 of sensitive individuals. The plant's volatile oils are metabolized in the liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

 into toxic compounds which can cause internal blood clotting and the formation of micro-thrombi
Thrombus
A thrombus , or blood clot, is the final product of the blood coagulation step in hemostasis. It is achieved via the aggregation of platelets that form a platelet plug, and the activation of the humoral coagulation system...

 in the liver and digestive tract.

Sagebrush leaves compare favorably to alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...

 for livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

 nutrition
Nutrition
Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....

 value. However, they also contain oils that are toxic to the symbiotic
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...

 bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 in the rumen
Rumen
The rumen, also known as a paunch, forms the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. It serves as the primary site for microbial fermentation of ingested feed...

 of most ruminant
Ruminant
A ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...

s. These oils have the greatest effect on cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

. Cattle that resort to sagebrush due to the lack of other fodder
Fodder
Fodder or animal feed is any agricultural foodstuff used specifically to feed domesticated livestock such as cattle, goats, sheep, horses, chickens and pigs. Most animal feed is from plants but some is of animal origin...

 in the winter often freeze to death before starving, as they rely in large part on the heat of their digestive
Digestion
Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....

 action for warmth. Ranchers call this condition "hollow belly". Sheep can tolerate moderate consumption of sagebrush leaves, especially the fresh spring buds. Pronghorn
Pronghorn
The pronghorn is a species of artiodactyl mammal endemic to interior western and central North America. Though not an antelope, it is often known colloquially in North America as the prong buck, pronghorn antelope, or simply antelope, as it closely resembles the true antelopes of the Old World and...

 are the only large herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...

 to browse sagebrush extensively. As pronghorn are the only remaining large herbivore that evolved
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

 along with sagebrush (deer
Deer
Deer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include white-tailed deer, elk, moose, red deer, reindeer, fallow deer, roe deer and chital. Male deer of all species and female reindeer grow and shed new antlers each year...

 are a more recent arrival from Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

), this is not surprising. There is speculation that some of the herbivores that went extinct in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 at the end of the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 such as the Ground Sloth
Ground sloth
Ground sloths are a diverse group of extinct sloths, in the mammalian superorder Xenarthra. Their most recent survivors lived in the Antilles, where it has been proposed they may have survived until 1550 CE; however, the youngest AMS radiocarbon date reported is 4190 BP, calibrated to c. 4700 BP...

 or the American Camel
Camel
A camel is an even-toed ungulate within the genus Camelus, bearing distinctive fatty deposits known as humps on its back. There are two species of camels: the dromedary or Arabian camel has a single hump, and the bactrian has two humps. Dromedaries are native to the dry desert areas of West Asia,...

 were also capable of browsing sagebrush.

Native Americans used sagebrush administered internally as a medicine to halt internal bleeding
Internal bleeding
Internal bleeding is bleeding occurring inside the body. It can be a serious medical emergency depending on where it occurs , and can potentially cause death and cardiac arrest if proper medical treatment is not received quickly....

 caused by battle wounds and childbirth. The plant is very toxic to internal parasites and was used to expel worm
Parasitic worm
Parasitic worms or helminths are a division of eukaryoticparasites that, unlike external parasites such as lice and fleas, live inside their host. They are worm-like organisms that live and feed off living hosts, receiving nourishment and protection while disrupting their hosts' nutrient...

s. The plant's oils are toxic to the liver and digestive system of humans if taken internally, with the toxic symptoms subsiding 24–48 hours after ingesting the plant.

A tea made from sagebrush was used internally and as a topical dressing
Dressing (medical)
A dressing is an adjunct used by a person for application to a wound to promote healing and/or prevent further harm. A dressing is designed to be in direct contact with the wound, which makes it different from a bandage, which is primarily used to hold a dressing in place...

 to treat infections by Native Americans in the Mountain West of North America.
Woven sagebrush was used to make sandals in prehistory.

See also

  • Medicinal plants of the American West
    Medicinal plants of the American West
    Many plants that grow in the American West are purported to have therapeutic properties by practitioners of alternative medicine.-Use and availability:European and Asian plants are commonly used in herbalism and are generally available in retail shops....

  • List of plants poisonous to equines
  • Sagebrush Cooperative
    Sagebrush Cooperative
    The Sagebrush Cooperative is collaborative group based in southeastern Oregon and adjacent portions of Idaho and Nevada involving land managers, owners, and interest groups with the goal of improved management and conservation of shrub steppe systems....

  • Sagebrush Billium

External links

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