''Pseudoroegneria spicata'' is a species of perennial

bunchgrass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennia ...

known by the common name bluebunch wheatgrass. It is native to western North America.

Description

Bluebunch wheatgrass can grow up to tall. It can often be distinguished from other bunchgrasses by the awns on its seedheads which stand out at an angle nearly 90 degrees from the stem. It is often bluish. The roots of the grass have a waxy layer that helps it resist

desiccation Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. The ...

in dry soils.US Forest Service Fire Ecology
/ref> In areas with more moisture the grass may produce

rhizome In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...

s. The relationship between the traits and climates of ''P. spicata'' is consistent with those of other grass species that also have a summer growing season. Populations of ''P. spicata'' from warm, arid environments are often smaller with earlier phenology, narrower leaves, and have greater leaf pubescence. This is in contrast to ''P. spicata'' plants from wetter and higher nutrient environments, which tend to be bigger, taller, and have larger leaves.St. Clair JB, Kilkenny F, Johnson R, Shaw N, Weaver G (2013) Genetic variation in adaptive traits and transfer zones for ''Pseudoroegneria spicata'' (bluebunch wheatgrass) in the northwestern United States. ''Evolutionary Applications'' 6 (3): 933-948. The stems and leaf sheaths of ''P. spicata'' dominate

photosynthetic Photosynthesis ( ) is a Biological system, system of biological processes by which Photoautotrophism, photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical ener ...

carbon uptake during the late spring and summer seasons. Additionally, bluebunch wheatgrass shows a greater investment of biomass and nutrients in the stems and sheaths, causing an increase in photosynthetic capacity per unit surface area. ''Pseudoroegneria spicata'' is most commonly found as a diploid (2n = 14), although autotetraploid forms (4n = 28) have been found in eastern Washington and northern Idaho.

Taxo

The species is also known by the scientific

synonyms 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 ...

''Elymus spicatus'' and ''Agropyron spicatum''. Two subspecies of bluebunch wheatgrass are recognized: ''P. spicata'' ssp''. spicata'' and ''P. spicata'' ssp. ''inerme'', commonly known as beardless bluebunch wheatgrass. The determining characteristic between the two is the presence of divergent awns, or hair-like projections that extend off a larger structure, such as the lemma or floret. These two subspecies have been known to hybridize.

Distribution and habitat

''Pseudoroegneria spicata'' can be found in the United States, Canada, and Mexico from

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

and

Yukon Yukon () is a Provinces and territories of Canada, territory of Canada, bordering British Columbia to the south, the Northwest Territories to the east, the Beaufort Sea to the north, and the U.S. state of Alaska to the west. It is Canada’s we ...

south as far as

Sonora Sonora (), officially Estado Libre y Soberano de Sonora (), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is divided into Municipalities of Sonora, 72 ...

and

Nuevo León Nuevo León, officially the Free and Sovereign State of Nuevo León, is a Administrative divisions of Mexico, state in northeastern Mexico. The state borders the Mexican states of Tamaulipas, Coahuila, Zacatecas, and San Luis Potosí, San Luis ...

. It is the dominant species of grass among the mountainous regions of the western United States, occurring at elevations that range from and where precipitation is . It occurs in many types of habitat, including sagebrush, forests, woodlands, and grasslands. This grass thrives in sandy and clay rich soils, but is also capable of growing on thin, rocky soils. It does not tolerate soils with high alkalinity, salt, or excessive moisture.

Ecology

''Pseudoregneria spicata'' has extensive drought-resistant root systems that can compete with and suppress the spread of exotic weeds.Jackson RB, Caldwell MM (1991) Kinetic responses of Pseudoroegneria roots to localized soil enrichment. ''Plant and Soil'' 138 (2): 231-238. Its roots are also known to have significant responses when they come into contact with the roots of other plants. When plants of the same species that were grown in different sites were planted in pots together, the resulting biomass was 30% more than in pots with plants from the same population or site. Furthermore, the elongation of the roots decreased after contact with roots from another plant from the same population, this was compared to after contact with roots from a plant of a different population. Such behavior suggests that the roots of bluebunch wheatgrass are capable of detection and avoidance mechanisms when exposed to intraspecific plants from the same population. The roots of this grass are also known to have notable physiological responses to enriched soil patches that are treated with varying solutions of nutrients, most notably nitrogen, potassium, and phosphorus. This exploitation of nutrient-rich soil can affect the nutrient status of the overall plant. In phosphorus enriched environments, the mean root uptake of phosphorus was 5–26% higher compared to roots from control soil patches. Results regarding the nutrient uptake capacities of ''P. spicata'' potassium enriched environments indicate no apparent difference between enriched and controlled soil. This is in contrast to the nitrogen enrichment experiment, where mean rates of ammonium uptake increased between 22–88% and mean rates of potassium root uptake were 17–71% higher in soil enriched with 50 μm of nitrogen, the lowest concentration tested in a particular study. ''Pseudoregneria spicata'' is outcompeted by

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is harmful to agricultural or horticultural crops, natural habitats or ecosystems, or humans or lives ...

s such as diffuse knapweed (''Centaurea diffusa'') and medusahead (''Taeniatherum caput-medusae''). It provides important

forage Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used m ...

for both

livestock Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...

and native

wildlife Wildlife refers to domestication, undomesticated animals and uncultivated plant species which can exist in their natural habitat, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introdu ...

in western North America.

Uses

The species is widely used for

revegetation Revegetation is the process of replanting and rebuilding the soil of disturbed land. This may be a natural process produced by plant colonization and succession, manmade rewilding projects, accelerated process designed to repair damage to a la ...

of degraded habitat in the region, and

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

s have been developed.Larson, S. R., et al. (2004)
Population structure in ''Pseudoroegneria spicata'' (Poaceae: Triticeae) modeled by Bayesian clustering of AFLP genotypes.
'' American Journal of Botany'' 91 1791-1801.

In culture

It is the state grass of

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

, and Washington.

References

External links

United States Department of Agriculture Plants ProfileUniversity of Washington, Washington Burke Museum
* {{Authority control Pooideae Bunchgrasses of North America Grasses of the United States Grasses of Canada Flora of Northern America Plants described in 1813 Symbols of Montana