Agropyron cristatum
(crested wheatgrass)

Preferred Common Name

• crested wheatgrass

Other Scientific Names

• Agropyron barginensis Skvortsov
• Agropyron brandzae Pantu & Solacolu
• Agropyron cristatiforme P.K.Sarkar
• Agropyron cristatum Besser
• Agropyron czerepanovii Tzvelev
• Agropyron dagnae Grossh.
• Agropyron distichum (Georgi) Peschkova
• Agropyron erickssonii (Melderis) Peschkova
• Agropyron hirsutum Ledeb.
• Agropyron imbricatum Roem. & Schult.
• Agropyron incanum (Nábelek) Tzvelev
• Agropyron karadaghense Kotov
• Agropyron karataviense Pavlov
• Agropyron kazachstanicum (Tzvelev) Peschkova
• Agropyron lavrenkoanum Prokudin
• Agropyron litvinovii Prokudin
• Agropyron muricatum (Link) Schult.
• Agropyron pachyrhizum A.Camus
• Agropyron pectinatum (M.Bieb.) P.Beauv.
• Agropyron pinifolium Nevski
• Agropyron ponticum Nevski
• Agropyron puberulum (Boiss. ex Steud.) Grossh.
• Agropyron pumilum (L.f.) P.Beauv.
• Agropyron sclerophyllum (Novopokr.) Novopokr.
• Agropyron stepposum Dubovik
• Agropyron tarbagataicum Plotn.
• Avena cristata (L.) Roem. & Schult.
• Brachypodium brachystachyum Voss
• Bromus cristatus L.
• Costia cristata (L.) Willk.
• Costia imbricata (Roem. & Schult.) Willk.
• Cremopyrum pectinatum (M.Bieb.) Schur
• Elymus pectinatus (M.Bieb.) Laínz
• Eremopyrum cristatum (L.) Willk. & Lange
• Eremopyrum puberulum (Boiss. ex Steud.) Grossh. ex Prokudin
• Festuca pectiniformis (Roem. & Schult.) A. V. Bukhteeva
• Kratzmannia cristata (L.) Skalicky & V.Jirasek
• Kratzmannia imbricata (Roem. & Schult.) Opiz
• Kratzmannia pectinata (M.Bieb.) Skalicky & V.Jirasek
• Secale pumilum (L.f.) Pers.
• Triticum caucasicum Spreng.
• Triticum cristatum (L.) Schreb.
• Triticum hirsutum Hornem.
• Triticum imbricatum M.Bieb.
• Triticum intermedium M.Bieb. ex Kunth
• Triticum muricatum Link
• Triticum pectinatum M.Bieb.
• Triticum pectiniforme Steud.
• Triticum puberulum Boiss. ex Steud.
• Triticum pumilum L.f.
• Zeia cristata (L.) Lunell

International Common Names

• English: crested wheat grass; fairway crested wheatgrass; fairway wheatgrass
• Spanish: agropiro crestado; agropiro de crista; triguillo crestado
• French: agropyre à crête; agropyron accrêté; chiendent à crête; chiendent pectiné
• Russian: zhitnyak grebenchatyi
• Chinese: bing cao

Local Common Names

• Czech Republic: pýr hrebenitý
• Denmark: kamkvik
• Finland: harjasvehnää
• Germany: Kammquecke
• Greece: agropiron to lofodes
• Hungary: taréjos búzafü
• Italy: agropiro crestato; gramigna crestata
• Japan: kuresuteddo hoiito gurasu
• Poland: perzyk grzebieniasty
• Sweden: kamvete
• Turkey: otlak ayrigi

EPPO code

• AGRCR (Agropyron cristatum)

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Monocotyledonae
•                     Order: Cyperales
•                         Family: Poaceae
•                             Genus: Agropyron
•                                 Species: Agropyron cristatum

The genus Agropyron in The Plant List (2013) includes 194 scientific plant names of species rank, of which only 26 are accepted species names. Also included are a further 163 scientific plant names of infraspecific rank. For A. cristatum, there are 122 synonyms and one unresolved name (Agropyron czerepanovii Tzvelev).

The genus owes its name to the Greek words agros (field, country) and pyron (grain of wheat) (Charters, 2015), referring to the resemblance of Agropyron plants to cultivated annual wheat (Watson and Dallwitz, 2015). Members of the genus are distributed throughout the temperate regions of the world (Watson and Dallwitz, 2015) and they frequently hybridize with each other, often producing fertile crosses (Dewey, 1983). A. cristatum readily crosses with A. desertorum to produce fertile hybrids (Zlatnik, 1999). In the past, these two have been considered a single species (Zlatnik, 1999). However, APG-III currently recognizes them as separate species (The Plant List, 2013).

A. cristatum was first described by Linnaeus as Triticum cristatum, and originally published as such by Schreber in 1770. The combination of cristatum with Agropyron by Gaertner was published in the same year (Gaertner, 1770). The Latin epithet cristatum means “crested”, alluding to this species’ crest-like inflorescence (Johnson and Smith, 1972).

A. cristatum is a perennial caespitose plant with a fibrous and finely branched root system, with most roots extending to a depth of 1 m. Culms decumbent, 20-70 cm long. Leaf-sheath oral hairs lacking. Leaf-sheath auricles falcate. Ligule an eciliate membrane, 2 mm long. Leaves are abundant, both at the base and along the stems. Leaf-blades involute, 6-12 cm long and 1.5-3 mm wide; stiff. The inflorescence may be lax or dense and is composed of racemes. Racemes single, oblong, bilateral, 1-5 cm long, 10-20 mm wide. Rachis pilose on the surface. The species has a dense spikelet, with a conspicuously flattened head. Spikelet packing broadside to rachis. Rachis internodes oblong. Spikelets pectinate; solitary. Fertile spikelets sessile, comprising 3-8 fertile florets, with diminished florets at the apex. Spikelets oblong, laterally compressed, compressed strongly, 8-15 mm long, breaking up at maturity and disarticulating below each fertile floret. Glumes persistent, shorter than spikelet, firmer than fertile lemma. Lower glume ovate, 3-5 mm long, 1.0 length of upper glume; coriaceous, 1-keeled, keeled all along, 3 -veined. Lower glume surface glabrous or pilose. Lower glume apex acuminate, awned, 1 -awned. Lower glume awn 1-2 mm long. Upper glume ovate, 3-5 mm long, 0.66 length of adjacent fertile lemma; coriaceous, 1-keeled, keeled all along, 3 -veined. Upper glume lateral veins convergent at apex. Upper glume surface glabrous or pilose. Upper glume apex acuminate, awned, 1 -awned. Upper glume awn 1-2 mm long. Fertile lemma elliptic, 5-7 mm long, chartaceous, keeled, keeled above; 5 -veined. Lemma surface pilose. Lemma apex acuminate, awned, 1 -awned. Principal lemma awn 3-4 mm long overall; limb scabrous. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped. Ovary with a fleshy appendage below style insertion; pubescent on apex. Caryopsis with adherent pericarp, oblong, sulcate on hilar side, hairy at apex, apex fleshy. Embryo 0.2 times the length of caryopsis. Hilum linear, 1.0 length of caryopsis. Disseminule comprising a floret (from Clayton et al., 2015).

A. cristatum was intentionally introduced by the US Department of Agriculture from Russia and Siberia, according to Zlatnik (1999) in 1906. However, Davison and Smith (1996) state that introduction to the USA occurred in 1898 as part of a governmental programme to identify valuable plants for introduction to the country. According to Dillman (1946), A. cristatum was first successfully established in the USA between 1907 and 1913. It became prevalent in the 1930s when it was used to seed abandoned cropland (Zlatnik, 1999).

Its ecological success has been such that it is estimated that between 5 and 26 million acres (2 to 10 million ha) of rangeland are now occupied by this weed in North America (Lesica and DeLuca, 1996; Pellant and Lysne, 2005; Grant-Hoffman et al., 2012). According to Asay et al. (1999), some of these A. cristatum communities have remained virtual monocultures for more than 50 years without apparent successional trends. It is now considered a weed in most parts of the world where it occurs (Global Compendium of Weeds, 2015), and is listed as an invasive plant by the USDA Forest Service (2015).

Soil drainage

• free

Soil reaction

• alkaline
• neutral

Soil texture

• heavy
• light
• medium

Special soil tolerances

• infertile

Natural Dispersal

Propagules of A. cristatum are wind dispersed (Marlette and Anderson, 1986).

Vector Transmission (Biotic)

In North America, the rodent Peromyscus maniculatus disperses the seeds of A. cristatum (Miller, 2010), while in Mongolia it was shown that seed attachment to the wool of sheep allowed for long distance dispersal by flocks (up to 15 km a day), with seeds remaining attached for hours and even days (Bläss et al., 2010).

Intentional Introduction

This species is intentionally introduced for agricultural or erosion-control purposes.

As a susceptible host of the pathogen Puccinia striiformis, it can act as a reservoir for infection, causing economic losses in cereal crops (Roelfs and Bushnell, 2014).

Impact on Habitats

It has been proven that by displacing native vegetation, A. cristatum alters rangeland soil chemical properties, reducing soil organic matter and increasing nitrate nitrogen and phosphorus contents, as well as soil chemical index and urease activity (Dormaar et al., 1995). Christian and Wilson (1999) found that in abandoned fields sown to A. cristatum the soil had significantly less available N, total nitrogen and total carbon than soils under successional prairie. Moreover, in areas dominated by A. cristatum, there is an increase in bare ground compared to native mixed grass prairie (Sutter and Brigham, 1998).

Impact on Biodiversity

Outside of its native range, A. cristatum has been identified as a driver for the loss of biodiversity in natural grasslands (Henderson and Naeth, 2010). For example, where sown in abandoned fields in the Great Plains, there were fewer native species than in the prairie, resulting in significantly lower species richness and diversity (Christian and Wilson, 1999). Working with historical data from western Colorado, Grant-Hoffman et al. (2012) found that after planting public lands to crested wheatgrass, the species increased in frequency significantly over time; however, of the other plant species present, only Elymus elymoides and Sporobolus cryptandrus decreased in frequency with increasing crested wheatgrass cover. Five species of grass, two shrubs and one forb were able to persist to various degrees.

The Goose Creek milkvetch (Astragalus anserinus), a low-growing, matted, perennial native forb, listed in the USA as a candidate species under the Endangered Species Act, grows only in a limited area of the Goose Watershed of the Upper Snake River Basin in Idaho, Nevada and Utah. Existing populations are threatened by wildfires, livestock trampling, rights of way and invasive non-native species. The non-native species of most concern to Goose Creek milkvetch are cheatgrass (Bromus tectorum), because of its tendency to increase the frequency of wildfires, and leafy spurge (Euphorbia esula) and crested wheatgrass, because of their ability to competitively displace the slower growing native, especially after disturbance events such as wildfires (US Fish and Wildlife Service, 2014). 

According to Reynolds and Trost (1980), areas where A. cristatum is cultivated can be less favourable not only for native plants, but also for birds and wildlife. The abundance and diversity of songbirds in Saskatchewan was thought to be reduced when mixed grass prairie was converted to more open crested wheatgrass habitat (Sutter and Brigham, 1998).

Planting of A. cristatum in large blocks within native rangelands is seen as reducing the aesthetic value of the rangeland landscape (Davison and Smith, 1996).

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Tolerant of shade
• Benefits from human association (i.e. it is a human commensal)
• Long lived
• Fast growing
• Has high reproductive potential
• Has propagules that can remain viable for more than one year

• Ecosystem change/ habitat alteration
• Modification of fire regime
• Modification of nutrient regime
• Modification of successional patterns
• Monoculture formation
• Negatively impacts agriculture
• Reduced amenity values
• Reduced native biodiversity
• Threat to/ loss of native species

• Competition - monopolizing resources
• Competition - shading
• Pest and disease transmission
• Hybridization
• Interaction with other invasive species
• Rapid growth

• Highly likely to be transported internationally deliberately
• Difficult to identify/detect as a commodity contaminant

Economic Value

As a fodder species, A. cristatum has high yields and is palatable to all classes of livestock and wildlife, and supplies green forage in both spring and autumn (Johnson, 1986; Mayland, 1986). Its seeds are easy to collect and sow with standard equipment, which is particularly important because cultivation can be carried out at an economically reasonable price (Johnson, 1986).This species is also a tertiary genetic relative of wheat (based on hybrid formation with Triticum aestivum) and is viewed as a genetic resource for wheat breeding (Limin and Fowler, 1990).

Social Benefit

According to Hannaway and Larson (2004) and Ogle (2006), various low-growing, rhizomatous strains of A. cristatum are used in lawns and turfs. Moreover, the species can be used in urban areas where irrigation water is limited to provide ground cover, weed control and to stabilize ditch banks, dikes, pipelines, power lines and roadsides (Ogle, 2006).

Environmental Services

A. cristatum has been used extensively for erosion control (Brown et al., 1985), as well as to revegetate burned and degraded land (Zlatnik, 1999). It is also a fire-retardant species that can help control wildfires in semi-arid rangelands (Green, 1977). In spite of its detrimental effects, one reason A. cristatum continues to be used in the USA is its ability to outcompete other more detrimental invasive plants such as cheatgrass (Bromus tectorum) (Francis and Pyke, 1996).

Moreover, A. cristatum is an important source of food for mule deer (Odocoileus hemionus) and pronghorn antelope (Antilocapra americana), particularly at times when other preferred food sources are unavailable (Urness, 1986). Crested wheatgrass is highly palatable to and good cover for black-tailed jackrabbits (Lepus californicus) (Ganskopp et al., 1993) as well as deer mice (Peromyscus spp.), montane voles (Microtus montanus), Ord's kangaroo rats (Dipodomys ordii) and Townsend's ground squirrels (Urocitellus townsendii) (Koehler and Anderson, 1991).