Fact Sheets


Bromus arvensis L.

Family :

Famille :


Synonym(s) :

Synonyme(s) :

Common Name(s) :

Nom(s) commun(s) :

Field brome
(English) (GC 2016)
Brome des champs (French) (GC 2016)

  • Field brome (Bromus arvensis) florets

  • Field brome (Bromus arvensis) florets

  • Bromus arvensis

  • Bromus arvensis

  • Bromus arvensis

  • Field brome (Bromus arvensis) palea teeth

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Regulation :

Remarques Réglementation:

  • CFIA Weed Seeds Order - Class 3: Secondary Noxious Weed Seeds

Regulation Notes:

Distribution :

Répartition :

Native to southern and south-central Europe and temperate Asia, and widely naturalized further north in Europe and in other temperate regions of the world (Tutin et al. 1980; Barkworth et al. 2007; USDA-ARS 2021). In the United States it occurs in several states, particularly on the east coast (Barkworth et al. 2007). In Canada, the species occurs in Ontario and Quebec (Brouillet et al. 2010+; Canadian Endangered Species Conservation Council 2016; Lavoie et al. 2012).

Habitat and Crop Association :

Habitat et Cultures Associées :

Roadsides, fields, forest margins and waste places (Barkworth et al. 2007). A weed of arable land in Europe, notably in winter cereals (Tutin et al. 1980). Adapted to the corn-belt region and eastwards in the United States (Williams et al. 2011) and sometimes grown for erosion control or as a cover crop to improve the soil (Wiersema and Leon 1999).

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:


Dispersal Unit Type :

Type d’unité de dispersion :


General Information


Bromus arvensis was introduced to North America as a cover crop in the 1920s, and now occurs in several U.S. states. In Canada it has persisted as a weed in experimental field plots at the University of Guelph in Ontario since 1933. Dore and McNeill (1980) noted that “this versatile and early maturing annual would be difficult to control if it became widely established”.




  • Spikelet


    • Spikelet length : 10.0 – 25.0 mm (Barkworth et al. 2007)


    • Spikelet long egg-shaped, cylindrical or laterally compressed in edge view

    Surface Texture

    • Spikelets are generally smooth with several longitudinal nerves


    • Spikelet is generally dull or shiny straw yellow, some may have purple patches

    Other Features

    • 4 – 10 florets in a spikelet (Barkworth et al. 2007)
  • Floret


    • Floret length* : 7.5 – 9.1 mm; width: 1.3 – 2.0 mm
    *Note: minimum and maximum of 10 florets in a normal range of this species using image measurement (ISMA 2020)


    • Long oval shaped floret, strongly compressed in edge view

    Surface Texture

    • Floret surface is generally smooth with several longitudinal nerves


    • Floret is dull or shiny straw yellow

    Other Features

    Lemma awn

    • Top of lemma splits into 2 pointed lobes, a straight awn arises between them
    • Lemma awn length: 6.0 – 11.0 mm (Barkworth et al. 2007)

    Callus and Rachilla

    • Rachilla cylindrical, bulging out below the scar
    • Tip of the rachilla is flat with a brown coloured, circular scar
    • Rachilla short hairy and curved towards the palea

    Other features

    • Sides of lemma may be straight or curled in, may be broken during processing
    • Palea is thin, can generally see the caryopsis behind it
    • Palea teeth are long, thin and widely spaced
    • The palea edges may extend beyond the palea teeth onto the caryopsis and are transparent with dense short hairs
    • Palea is as long as the lemma, but may be broken during processing
  • Caryopsis 


    • Caryopsis length*: 6.0 – 7.0 mm; width: 1.5 – 1.8 mm
    *Note: minimum and maximum of 5 caryopses in a normal range of this species using specimen measurement (ISMA 2020)


    • Caryopsis is long oval shaped, thin, generally with edges curled in

    Surface Texture

    • Caryopsis is a smooth texture


    • Caryopsis is reddish coloured

    Other Features

    • Caryopsis is generally shorter than both the lemma and the palea
    • A linear, black coloured hilum extends the length of the caryopsis
  • Embryo


    • Embryo is a rudimentary size compared to the caryopsis


    • Embryo is oval or wedge-shaped and located at an end of one flat side of the caryopsis


    • Endosperm is hard and opaque white coloured

Identification Tips


The florets of Bromus arvensis are similar to other Bromus species with a thin caryopsis and long palea teeth such as B. japonicus and B. hordeaceus. The florets of B. arvensis generally have a curled caryopsis that is shorter than the palea and lemma, small hairs between the palea edge and the caryopsis edge, palea is a similar length as the lemma, and a straight awn. The caryopsis of B. japonicus is generally flat and a similar size as the palea, the lemma has a curved awn and the palea is shorter than the lemma. B. hordeaceus florets do not have hairs between the palea and the edge of the flat caryopsis.

Additional Botany Information


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.

Bromus japonicus Houtt. (Japanese brome)

The florets of B. japonicus are a similar size (length*: 7.1 – 9.2mm; width: 1.3 – 1.7 mm) as B. arvensis with lemmas that are generally scabrous and have a longer awn (8.0 – 13.0 mm; Barkworth et al. 2007) that curves away from the lemma. The caryopsis is a similar length as the palea with edges that rarely curl inwards and the palea is shorter than the lemma compared to B. arvensis florets.

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

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

Brouillet, L., Coursol, F., Meades, S. J., Favreau, M., Anions, M., Bélisle, P. and Desmet, P. 2010+. VASCAN, the database of vascular plants of Canada. http://data.canadensys.net/vascan/ Accessed March 3, 2021.

Canadian Endangered Species Conservation Council. 2016. Wild Species 2015: The General Status of Species in Canada. National General Status Working Group.

Dore, W. G. and McNeill, J. 1980. Grasses of Ontario. Minister of Supply and Services Canada, Hull, Quebec. 566 pp.

Flora of North America (FNA) Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. New York and Oxford.  Accessed December 29, 2022.

Global Biodiversity Information Facility (GBIF) Secretariat. 2022. https://doi.org/10.15468/39omei Accessed via https://www.gbif.org/species/2703705 Accessed December 29, 2022.

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)

International Seed Morphology Association (ISMA). 2020. Method for Seed Size Measurement. Version 1.0. ISMA Publication Guide.   https://www.idseed.org/authors/details/method_for_seed_size_measurement.html

Lavoie, C., Saint-Louis, A., Guay, G. & Groeneveld, E. 2012. Les plantes vasculaires exotiques naturalisées: une nouvelle liste pour le Québec. Le Naturaliste canadien 136(3):6 https://doi.org/10.7202/1009237ar Accessed March 3, 2021.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. and Webb, D. A. (eds.) 1980. Flora Europaea. Volume 5: Alismataceae to Orchidaceae (Monocoyledones). Cambridge University Press, Cambridge, UK.

U.S. Department of Agriculture-Agricultural Research Services (USDA-ARS). 2021. Germplasm Resources Information Network (GRIN), https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx Accessed March 3, 2021.

Wiersema, J. H. and León, B. 1999. World Economic Plants: A Standard Reference CRC Press, Boca Raton, Florida.

Williams, W. M., Stewart, A. V. and Williamson, M. L. 2011. Bromus. in Kole, C., eds. Wild Crop Relatives: Genomic and Breeding Resources, Millets and Grasses. Springer-Verlag, Berlin & Heidelberg. 15-30 pp.



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

Canadian Food Inspection Agency