Fact Sheets


Aegilops cylindrica Host

Family :

Famille :


Synonym(s) :

Synonyme(s) :

Cylindropyrum cylindricum (Host) Á. Löve (FNA 1993+; USDA-ARS 2020; POWO 2022; Tropicos 2022)

Triticum cylindricum (Host) Ces. (FNA 1993+; USDA-ARS 2020; POWO 2022; Tropicos 2022)

Aegilops cylindrica Host subsp. pauciaristata Eig           (USDA-ARS 2020; Tropicos 2022)

Common Name(s) :

Nom(s) commun(s) :

Jointed goatgrass
(English) (GC 2016; Tropicos 2022)
Égilope cylindrique (French) (GC 2016)
Shan yang cao (Chinese) (CABI 2020)
Cylindrical hard-grass (English) (CABI 2020)
Égilope a queue (French) (CABI 2020)

  • Aegilops cylindrica (jointed goatgrass) spikelet segments

  • Aegilops cylindrica (jointed goatgrass) spikelet segments

  • Aegilops cylindrica (jointed goatgrass) spikelet segments

  • Aegilops cylindrica (jointed goatgrass) spikelet segment showing glume

  • Aegilops cylindrica (jointed goatgrass) spikelet segment interior

  • Aegilops cylindrica (jointed goatgrass) fertile florets

  • Aegilops cylindrica (jointed goatgrass) caryopsis

  • Aegilops cylindrica (jointed goatgrass) caryopsis

  • Aegilops cylindrica (jointed goatgrass) spikelet segments and interior: sterile floret, fertile florets, and caryopses

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Regulation :

Remarques Réglementation:

  • CFIA Weed Seeds Order - Class 1: Prohibited Noxious Weed Seeds
  • List of Pests Regulated by Canada
  • USA Federal Noxious Weed Seed List

Regulation Notes:

Prohibited Noxious, Class 1 in the Canadian Weed Seeds Order (2016) under the Seeds Act. All imported and domestic seed must be free of Prohibited Noxious weed seeds.

Distribution :

Répartition :

Native to southeastern Europe and western Asia. Introduced and widespread in Europe, North Africa and the United States, particularly in the western states (Donald and Ogg 1991; CABI 2020). Limited Canadian populations are under official control.

Habitat and Crop Association :

Habitat et Cultures Associées :

Cultivated fields, pastures and disturbed areas along fences, ditches and roadsides. A major weed of Triticum aestivum subsp. aestivum (common wheat) (Donald and Ogg 1991; CABI 2020).

Economic Use, cultivation area, and Weed Association :

Utilisation économique, zone de culture et association de mauvaises herbes :

Duration of Life Cycle :

Durée du cycle vital:

Winter annual

Dispersal Unit Type :

Type d’unité de dispersion :

Shed as a spikelet embedded in a stem segment. Each spikelet segment contains an average of 2 viable seeds (Donald and Ogg 1991).

General Information


Aegilops cylindrica was introduced into North America likely in the late 1800s through contaminated Triticum aestivum subsp. aestivum (common wheat) (Donald and Ogg 1991). It persisted and spread into common wheat growing areas in the western and central United States (CABI 2020). This species is genetically related to common wheat and can form natural hybrids (CABI 2020).

A. cylindrica plants can produce more than 3000 seeds per plant (CABI 2020). The stem breaks into spikelet segments during harvesting and the seed inside remains viable for several years (CABI 2020). The similar size and shape to common wheat make the segments of A. cylindrica difficult to clean out and can cause yield losses of 25 – 29 % in the field (Hubbard et al. 1997).


Aegilops cylindrica infestation in the United States (USDA APHIS PPQ – Oxford, North Carolina , USDA APHIS PPQ, Bugwood.org)



  • Spikelet segment


    • Spikelet segment length*: 12.0 – 14.3 mm; width: 3.0 – 4.3 mm
    *Note: minimum and maximum of 10 spikelet segments in a normal range of this species using image measurement (ISMA 2020)


    • Spikelet segment is cylindrical with flat ends

    Surface Texture

    • Surface of spikelet segment has longitudinal ridges and short hairs along those ridges


    • Spikelet segments are dull or shiny straw-yellow or light brown, some are purplish tinged

    Other Features

    Glume awn

    • Spikelet glumes from the lower part of the spike (inflorescence) may have awns 2.0 – 5.0 mm long (Barkworth et al. 2007)
    • Spikelet glumes from the upper part of the spike have longer awns 30.0 – 60.0 mm (Barkworth et al. 2007)

    Other features

    • The stem segment that the spikelets are embedded in floats in water
    • Glumes are rectangular shaped
    • Spikelet segments are shiny green when immature
  • Floret


    • Floret length: 9.0 – 10.0 mm (Barkworth et al. 2007)


    • Floret is oval shaped (CABI 2020)

    Surface Texture

    • Floret surface is smooth


    • Floret is dull straw yellow

    Other Features

    Lemma awn

    • Lemma awn length of spikelets near the bottom of the inflorescence: 1.0 – 5.0 mm (Barkworth et al. 2007)
    • Lemma awn length of spikelets near the top of the inflorescence: 40.0 – 80.0 mm (Barkworth et al. 2007)

    Other features

    • Each spikelet has 3-5 florets, and only 2-3 are fertile (Barkworth et al. 2007)
  • Caryopsis


    • Caryopsis length: 6.0 – 7.0 mm (Barkworth et al. 2007)


    • Caryopsis is long oval shaped with a pointed embryo end, plano-convex in edge view

    Surface Texture

    • Caryopsis is finely wrinkled


    • Caryopsis is dull straw yellow or orange

    Other Features

    • The floret adheres to the caryopsis
  • Embryo


    • Embryo is a rudimentary size compared to the caryopsis


    • Embryo is wedge-shaped in a lateral position at one end of the caryopsis


    • Endosperm is hard and opaque white coloured
  • Short Embryo Test


    Short Embryo Test


    Short Embryo Test


    Short Embryo Test

    Other Features

    Short Embryo Test

Identification Tips


The dispersal unit of Aegilops species are characterized by cylindrical or egg-shaped spikelets that are dispersed attached to a piece of the stem. The glumes are generally longitudinally ridged with long awns (Barkworth et al. 2007).

A. cylindrica is distinguished from other species in the genus by cylindrical spikelet segments, rectangular glumes and generally short awns. The other species in this genus generally have egg-shaped spikelet segments and the majority have oval-shaped glumes with long awns (Barkworth et al. 2007).

Additional Botany Information



  • Spikelet segments are connected together into a cylindrical spike, 22.0 – 120.0 mm long (Barkworth et al. 2007)


Similar Species


Similar species are based on a study of seed morphology of various species, and those with similar dispersal units are identified. The study is limited by physical specimen and literature availability at the time of examination, and possibly impacted by the subjectivity of the authors based on their knowledge and experience. Providing similar species information for seed identification is to make users aware of similarities that could possibly result in misidentification.

Rottboellia cochinchinensis (Lour.) Clayton

The spikelet segments of R. cochinchinensis are shorter (length*: 3.8 -7.5 mm) than A. cylindrica and lack surface hairs and awns.

Parapholis incurva (L.) C. E. Hubb.

The spikelet segments of P. incurva are generally smaller (length: 4.5 – 7.5 mm) (Barkworth et al. 2007) than A. cylindrica, may be straight or curved, with wedge-shaped glumes. This species grows in coastal habitats and salt marshes (Barkworth et al. 2007)

Aegilops triuncialis L.

The spikelet segments of A. triuncialis are generally smaller (length: 7.0 – 13.0 mm) (Barkworth et al. 2007) than A. cylindrica, and are oval shaped or almost cylindrical and glumes generally have longer awns 15.0 – 60.0 mm long (Barkworth et al. 2007) than A. cylindrica.

*Note: minimum and maximum of 10 spikelet segments in a normal range of this species using image measurement (ISMA 2020)

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Barkworth, M. E., K. M. Capels, S. Long, and M.B. Piep, (eds.) 2007. Flora of North America Volume 24. Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Oxford University Press, New York, New York.

Centre for Agriculture and Bioscience International (CABI). 2020. Invasive Species Compendium, CAB International, Wallingford, UK. https://www.cabidigitallibrary.org/journal/cabicompendium Accessed Sept. 16, 2020 .

Donald, W. and Ogg, A. 1991. Biology and Control of Jointed Goatgrass (Aegilops cylindrica), a Review. Weed Technology 5: 3-17.

Government of Canada (GC). 2016. Canadian Weed Seeds Order. https://laws-lois.justice.gc.ca/eng/regulations/SOR-2016-93/page-2.html (English) https://laws-lois.justice.gc.ca/fra/reglements/DORS-2016-93/page-2.html (French)

Hubbard, C. M., Weller, C. L. and Jones, D. D. 1997. Selected physical properties of Jointed goatgrass (Aegilops cylindrica). Applied Engineering in Agriculture. VOL. 13(6):747-750.

International Seed Morphology Association (ISMA). 2020. Method for Seed Size Measurement. Version 1.0. ISMA Publication Guide.

Plants of the World Online (POWO). 2022. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://www.plantsoftheworldonline.org/ Accessed April 29, 2022.

Tropicos.org. 2022. Missouri Botanical Garden. https://tropicos.org Accessed April 29, 2022.

U.S. Department of Agriculture-Agricultural Research Services (USDA-ARS). 2020. Germplasm Resources Information Network (GRIN), https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx Accessed May 13, 2020.



Jennifer Neudorf, Angela Salzl, Ruojing Wang, Karen Castro, Katrina Entwistle

Canadian Food Inspection Agency