Agropyron cristatum
Encyclopedia
Agropyron cristatum is a species
in the Poaceae
family. This plant is often used as forage
and erosion
control. It is well-known as a widespread introduced species
on the prairies of the United States.
referred to as Crested Wheatgrass. It is unable to hybridize with its similar relatives, as it is a diploid species, whereas its closest relative, A. desortum, is a tetraploidal species. It was introduced from Russia and Siberia to North America in the first half of the twentieth century, and widely used to reseed abandoned marginal cropland undergoing varying degrees of soil erosion and secondary succession. A. cristatum is very long lived, with stands often remaining productive for 30 years or more.
A. cristatum is the most shade-tolerant of the Crested Wheatgrasses, but does best in open conditions. A. cristatum is extremely drought tolerant. It achieves this drought tolerance by starting growth very early in the season, then going dormant from seed set until fall when it will exhibit vegetative regrowth if moisture is sufficient.
A. cristatum is very tolerant of grazing, although under dry conditions new stands should be protected from grazing for at least two years as the seedling are slow to develop. A. cristatum can be damaged by several fungi, including leaf and stripe rusts, snow mold and some arthropods including black grass bugs (Labops sp.) in pure plantings.
It is an easy grass to establish by seed, having both high germination rates and high seedling vigour. It also establishes rapidly relative to many other grasses. Under non-irrigated conditions in low precipitation areas, Crested Wheatgrasses are consistently some of, if not the, highest yielding and persistent of domestic forage grasses. However, A. cristatum is lower yielding, although it is slightly more palatable, relative to other Crested Wheatgrasses.
A. cristatum is a highly competitive and persistent plant in drier areas, and has a moderate ability to spread by seed. As such, its use in and adjacent to remaining natural grassland communities within its adapted areas in outside its native Eurasian distribution has come under criticism as a factor in natural grassland biodiversity loss, although the subject is still being studied.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
in the Poaceae
Poaceae
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
family. This plant is often used as forage
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...
and erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
control. It is well-known as a widespread introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
on the prairies of the United States.
History
Agropyron cristatum is one of several closely related grass speciesSpecies
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
referred to as Crested Wheatgrass. It is unable to hybridize with its similar relatives, as it is a diploid species, whereas its closest relative, A. desortum, is a tetraploidal species. It was introduced from Russia and Siberia to North America in the first half of the twentieth century, and widely used to reseed abandoned marginal cropland undergoing varying degrees of soil erosion and secondary succession. A. cristatum is very long lived, with stands often remaining productive for 30 years or more.
Description
A. cristatum is a densely tufted grass, with culms ranging from 30-50 cm high at maturity. Its sheaths are scabrous or the lowest ones pubescent. Its blades are up to 8 mm wide, and scabrous to pubescent above. Its spikes are flat and range from 2-7 cm long., with spikelets ranging from 8-15 mm long, being 3-5-flowered, densely crowded, and spreading to ascending. Its glumes are 4-6 mm long, awn-tipped, and its lemmas are 6-8 mm long and either awnless or awn-tipped.Habitat
A. cristatum is best adapted to dry rangeland conditions and is most frequently found in such circumstances. It prefers from 23 to 38 cm of precipitation per year, but can tolerate more moisture on favourable sites, extending its range into tundra and taiga conditions., and elevations up to 2000m above sea level in the southern portions of its adapted area. It prefers well drained, deep, loamy soils of medium and moderately course texture, including Chernozemic, Solonetzic, Regosolic, Brunisolic and Luvisolic soils. A. cristatum can tolerate salinity in the range of 5 to 15 mS/cm and prefers moderately alkaline conditions. It has low to medium fertility requirements. It will not tolerate prolonged flooding.A. cristatum is the most shade-tolerant of the Crested Wheatgrasses, but does best in open conditions. A. cristatum is extremely drought tolerant. It achieves this drought tolerance by starting growth very early in the season, then going dormant from seed set until fall when it will exhibit vegetative regrowth if moisture is sufficient.
A. cristatum is very tolerant of grazing, although under dry conditions new stands should be protected from grazing for at least two years as the seedling are slow to develop. A. cristatum can be damaged by several fungi, including leaf and stripe rusts, snow mold and some arthropods including black grass bugs (Labops sp.) in pure plantings.
Uses
A. cristatum has been bred into many cultivars selected for attributes ranging from forage yield to drought tolerance to turf types that will exhibit more pronounced degrees of rhizomatous growth habit. It has been, and continues to be, widely used in both agricultural and industrial reclamation activities.It is an easy grass to establish by seed, having both high germination rates and high seedling vigour. It also establishes rapidly relative to many other grasses. Under non-irrigated conditions in low precipitation areas, Crested Wheatgrasses are consistently some of, if not the, highest yielding and persistent of domestic forage grasses. However, A. cristatum is lower yielding, although it is slightly more palatable, relative to other Crested Wheatgrasses.
A. cristatum is a highly competitive and persistent plant in drier areas, and has a moderate ability to spread by seed. As such, its use in and adjacent to remaining natural grassland communities within its adapted areas in outside its native Eurasian distribution has come under criticism as a factor in natural grassland biodiversity loss, although the subject is still being studied.