Bromus diandrus (great brome)
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Plant Type
- Distribution Table
- Biology and Ecology
- Soil Tolerances
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Plant Trade
- Impact Summary
- Threatened Species
- Risk and Impact Factors
- Similarities to Other Species/Conditions
- Prevention and Control
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Bromus diandrus Roth
Preferred Common Name
- great brome
Other Scientific Names
- Anisantha diandra (Roth) Tutin
- Bromus gussonei Parl.
- Bromus gussonii Parl.
- Bromus maximus var. gussonei (Parl.) Parl.
- Bromus rigidus subsp. gussonei (Parl.) Maire
- Bromus rigidus var. gussonei (Parl.) Coss. & Durieu
International Common Names
- English: giant brome; great bromegrass
- Spanish: bromo
- French: brome raide
- Portuguese: espigao
Local Common Names
- Germany: Diandrus-Trespe; Grosse Trespe
- Italy: forasacco di Gussone
- BRODI (Bromus diandrus)
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Monocotyledonae
- Order: Cyperales
- Family: Poaceae
- Genus: Bromus
- Species: Bromus diandrus
Notes on Taxonomy and NomenclatureTop of page The synonym Anisantha diandra has been used until quite recently in Europe (e.g., Stace, 1991), this genus name being applied to species otherwise included in Bromus section Genea, differing from Bromus sensu stricto in having spikelets almost straight-sided, widening towards the top, rather than ovate to lanceolate, and having glumes with only one to three veins.
Bromus diandrus and B. rigidus are very closely related. In the USA, they are considered as one species. B. rigidus is treated as a subspecies of B. diandrus by Tsvelev (1984) (but in the genus Anisantha, as A. diandra subsp. rigida) and O'Connor (1990). A modern re-assessment of the taxonomy and nomenclature of the annual taxa within the mainly Mediterranean/southwestern Asiatic Bromus section Genea is given by Sales (1993) in which B. sterilis, B. diandrus and B. rigidus are considered as varieties of one species while recognizing that they have often been treated as separate species in recent floras. For the purposes of this Compendium, these three taxa are covered by separate species datasheets.
DescriptionTop of page B. diandrus is an annual plant, 30-90 cm high. Stout stem, hairy below panicle. Leaves 10 mm wide, rough with some long hairs; ligule prominent, 3-6 mm long, membranous, jagged tipped. Panicle loose, nodding, 15-20 cm long, pale green becoming purple-red. Spikelet branches longer than spikelets. Spikelets 25-40 mm long, 5-8 flowered. Glumes unequal, 1- to 3-nerved. Lemmas 20-35 mm long, finely 2-toothed with awn 35-60 mm long. Disarticulating above the glumes. Grain 9-11 mm long, hairy at the tip. Awn length 35-55 mm (Clapham et al., 1952; Hubbard, 1959; Cooper and Moerkerk, 2000; Weiller et al., 2005).
Plant TypeTop of page Annual
Grass / sedge
DistributionTop of page B. diandrus is indigenous to the Mediterranean region (Cooper and Moerkerk, 2000). Native records are based on USDA-ARS (2004; as Bromus diandrus var. diandrus) and Royal Botanic Garden Edinburgh (2004).
B. diandrus and other awned Bromus spp. were widespread weeds in Australia by the mid-1800s, but it was not until 1986 that B. rigidus was reported (Cooper and Moerkerk, 2000). In Australia there appears to be a continuum between typical B. diandrus and B. rigidus types (Cooper and Moerkerk, 2000).
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.Last updated: 10 Jan 2020
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Egypt||Present||Native||Cooper and Moerkerk (2000); USDA-ARS (2004)|
|South Africa||Present||Introduced||Cooper and Moerkerk (2000)|
|India||Present, Localized||Native||Bor (1960)|
|Israel||Present||Native||Cooper and Moerkerk (2000); USDA-ARS (2004)|
|Japan||Present||Introduced||Cooper and Moerkerk (2000)|
|Jordan||Present||Native||Cooper and Moerkerk (2000); USDA-ARS (2004)|
|Saudi Arabia||Present, Localized||Native||Hosni and Hegazy (1996)|
|South Korea||Present||Introduced||Cooper and Moerkerk (2000)|
|Syria||Present||Native||Cooper and Moerkerk (2000); USDA-ARS (2004)|
|Turkey||Present||Native||Cooper and Moerkerk (2000); Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|Uzbekistan||Present||Native||Cooper and Moerkerk (2000)|
|Belgium||Present||Introduced||Royal Botanic Garden Edinburgh (2004)|
|Cyprus||Present||Native||Cooper and Moerkerk (2000); USDA-ARS (2004)|
|France||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|-Corsica||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|Greece||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|-Crete||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|Italy||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|-Sardinia||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|-Sicily||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|Portugal||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|-Azores||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|Serbia and Montenegro||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|Spain||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|-Balearic Islands||Present||Native||Royal Botanic Garden Edinburgh (2004); USDA-ARS (2004)|
|-Canary Islands||Present||Native||USDA-ARS (2004)|
|Ukraine||Present||Introduced||Royal Botanic Garden Edinburgh (2004)|
|United Kingdom||Present||Introduced||Royal Botanic Garden Edinburgh (2004)|
|Mexico||Present||Mejía-Saulés et al. (2002)|
|United States||Present||Introduced||Cooper and Moerkerk (2000)|
|-California||Present||Native||Hoopes and Hall (2002)|
|-Hawaii||Present||Introduced||Holm et al. (1979)|
|Australia||Present||CABI (Undated)||Present based on regional distribution.|
|-New South Wales||Present||Introduced||Weiller et al. (1995)|
|-Queensland||Present||Introduced||Cooper and Moerkerk (2000)|
|-South Australia||Present||Introduced||Weiller et al. (1995); Cooper and Moerkerk (2000)|
|-Tasmania||Present||Introduced||Weiller et al. (1995)|
|-Victoria||Present||Introduced||Weiller et al. (1995)|
|-Western Australia||Present||Introduced||Weiller et al. (1995); Cooper and Moerkerk (2000)|
|New Zealand||Present||Introduced||Cooper and Moerkerk (2000)|
HabitatTop of page B. diandrus is a mainly a plant of waste places and fallow land but also occurs in shallowly tilled crop land. It tolerates a wide range of climates and grows on acidic or alkaline, sandy or loamy soils (Cooper and Moerkerk, 2000).
Biology and EcologyTop of page Genetics
The chromosome number is 2n = 56 (Kon and Blacklow, 1988).
B. diandrus germinates, grows and produces seeds during the winter, spring and early summer. In Australia, the closely related species B. rigidus matured earlier than B. diandrus, but there was high genetic variation in the time of maturity of both species (Kon and Blacklow, 1988). Seed production can range from 600 to over 3000 seeds per plant (Cooper and Moerkerk, 2000).
For more details of Bromus biology, see the datasheet on B. rigidus. For further detail on the biology of B. diandrus (and B. rigidus) refer to Groves et al. (1995).
Soil TolerancesTop of page
Notes on Natural EnemiesTop of page Studies have been conducted in the UK to investigate the potential of Pyrenophora chaetomioides (Lawrie et al., 1998) and P. semeniperda (Medd and Campbell, 2005) as mycoherbicides for B. diandrus and other Bromus spp.
Means of Movement and DispersalTop of page In general, propagation is by seed. Long-distance dispersal could occur by contamination of crop seeds and forages, attachment to animals or transport in ship ballast (Cooper and Moerkerk, 2000).
Plant TradeTop of page
|Plant parts liable to carry the pest in trade/transport||Pest stages||Borne internally||Borne externally||Visibility of pest or symptoms|
|True seeds (inc. grain)||seeds||Yes||Pest or symptoms usually visible to the naked eye|
Impact SummaryTop of page
|Fisheries / aquaculture||None|
ImpactTop of page In Australia, B. diandrus competes strongly with wheat. A density of 100 plants/m² of B. diandrus decreases wheat yield by 30% (Cooper and Moerkerk, 2000). B. diandrus is also becoming an increasing problem in arable crops in New Zealand where moderate infestations may reduce grain yields by 25-30% (Dastgeib et al., 2003).
In addition, Bromus species can host cereal diseases and are contaminants of grain and wool and they damage animal hides. In pastures, the seeds penetrate eyes, mouths and feet of animals and working dogs (Cooper and Moerkerk, 2000).
Threatened SpeciesTop of page
|Threatened Species||Conservation Status||Where Threatened||Mechanism||References||Notes|
|Brodiaea pallida (Chinese Camp brodiaea)||NatureServe; USA ESA listing as threatened species||California||Competition - monopolizing resources||US Fish and Wildlife Service, 2012|
|Chorizanthe pungens (Monterey spineflower)||NatureServe; USA ESA listing as threatened species||California||Competition (unspecified)||US Fish and Wildlife Service, 2009b|
|Dipodomys stephensi (Stephens' kangaroo rat)||EN (IUCN red list: Endangered)||California||Ecosystem change / habitat alteration||US Fish and Wildlife Service, 1997|
|Lithophragma maximum (San Clemente Island woodland-star)||NatureServe; USA ESA listing as endangered species||California||Competition - monopolizing resources||US Fish and Wildlife Service, 1984; US Fish and Wildlife Service, 2007|
|Oenothera deltoides subsp. howellii (Antioch Dunes evening-primrose)||NatureServe; USA ESA listing as endangered species||California||Competition - monopolizing resources||US Fish and Wildlife Service, 2008b|
|Phacelia insularis var. insularis (island phacelia)||NatureServe; USA ESA listing as endangered species||California||Competition (unspecified)||US Fish and Wildlife Service, 2008a|
|Speyeria callippe callippe (callippe silverspot butterfly)||USA ESA listing as endangered species||California||Ecosystem change / habitat alteration||US Fish and Wildlife Service, 2009a|
|Verbesina dissita (big-leaved crownbeard)||National list(s); USA ESA listing as threatened species||California||Competition - monopolizing resources||US Fish and Wildlife Service, 2010|
Risk and Impact FactorsTop of page Invasiveness
- Proved invasive outside its native range
- Highly adaptable to different environments
- Highly mobile locally
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Ecosystem change/ habitat alteration
- Negatively impacts agriculture
- Negatively impacts animal health
- Competition - monopolizing resources
- Competition (unspecified)
- Pest and disease transmission
- Highly likely to be transported internationally accidentally
Similarities to Other Species/ConditionsTop of page All Bromus species are very similar at the seedling and vegetative stages. B. diandrus is particularly difficult to distinguish from B. rigidus at all development stages (Cooper and Moerkerk, 2000). B. rigidus differs from B. diandrus in having shorter, sparser hairs on leaf laminae and more compact and erect panicles with shorter spikelet branches. In B. rigidus, the abscission scars on the rachillae are elliptical and the lemma calluses are elongated (>1 mm), whereas in B. diandrus, these characters were circular and short <1 mm) (Kon and Blacklow, 1988; Cooper and Moerkerk, 2000).
Prevention and ControlTop of page
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.A range of herbicide treatments has been successfully used for control of B. diandrus in Spain, South Africa, Australia and New Zealand. In cereals, these include pre-emergence applications of cyanazine + terbuthylazine, chlorsulfuron + terbuthylazine, and metribuzin (Dastgeib et al., 2003) though some tolerance of metribuzin is reported from Spain (Villaroya et al., 2001); or post-emergence applications of clethodim, haloxyfop (Nott, 2002); or sulfosulfuron (Agenbag and Crous, 1999). In legumes, post-emergence treatments include fluazifop, quizalofop (le Roux et al., 1995) and simazine + paraquat (Leys and Plater, 1993).
ReferencesTop of page
Agenbag GA, Crous R, 1999. Bromus diandrus Roth. control with MON 37532 in spring wheat (Triticum aestivum L.). 1. Time of application and dosage rate. South African Journal of Plant and Soil, 16(3):118-122; 5 ref.
Bor NL, 1960. The Grasses of Burma, Ceylon, India and Pakistan (Excluding Bambusae). Oxford, UK: Pergamon Press.
Clapham AR, Tutin TG, Warburg EF, eds, 1952. Flora of the British Isles. Cambridge, UK: Cambridge University Press.
Clayton WD, 1970. Gramineae (Part 1). In: Milne-Redhead E, Polhill RM, eds. Flora of Tropical East Africa. London, UK: Crown Agents for Oversea Governments and Administrations.
Cooper J, Moerkerk M, 2000. Bromus diandrus, Bromus rigidus. Weed ID/ Management. Australia. http://weedman.horsham.net.au/weeds/bromus_spp/bromus.htm.
Dastgeib F, Rolston MP, Archie WJ, 2003. Chemical control of brome grasses (Bromus spp.) in cereals. Proceedings of a conference, Christchurch, New Zealand, 12-14 August 2003. New Zealand Plant Protection, 56:227-232.
Hubbard CE, 1959. Grasses. Harmondsworth, UK: Penguin Books.
INRA, 2001. HYPPA. Hypermedia for Plant Protection - Weeds. Dijon, France: Institut National de la Recherche Agronomique. http://www.dijon.inra.fr/malherbo/hyppa/hyppa-a/hyppa_a.htm.
Kon KF, Blacklow WM, 1988. Identification, distribution and population variability of great brome (Bromus diandrus Roth) and rigid brome (Bromus rigidus Roth). Australian Journal of Agricultural Research, 39(6):1039-1050
Lawrie J, Greaves MP, Down VM, 1998. Drechslera sp. (Pyrenophora chaetomioides (Speg.)), a potential biocontrol agent for Bromus sterilis and other Bromus spp. Biocontrol Science and Technology, 8(4):479-484.
le Roux DJ, Agenbag GA, Mills LJ, 1995. Effect of grass weed control in legume-based annual pastures on yield potential of the succeeding wheat crop. Applied Plant Science, 9(2):39-42.
Medd RW, Campbell HA, 2005. Grass seed infection following inundation with Pyrenophora semeniperda. Biocontrol Science and Technology, 15(1):21-36.
Nott P, 2002. A low-rate spike of Verdict 520 with Select Herbicide improves control of key grass weeds. 13th Australian Weeds Conference: weeds "threats now and forever?", Sheraton Perth Hotel, Perth, Western Australia, 8-13 September 2002: papers and proceedings, 352-354; 2 ref.
O’Connor P, 1990. Poaceae. In: Wagner WL, Herbst DR, Sohmer SH, eds. Manual of the Flowering Plants of Hawai`i. Honolulu, Hawaii: University of Hawaii Press & Bishop Museum Press, 1481-1604.
Royal Botanic Garden Edinburgh, 2004. Flora Europaea Database. Royal Botanic Garden Edinburgh, UK. http://rbg-web2.rbge.org.uk/FE/fe.html.
Stace C, 1991. New Flora of the British Isles. Cambridge, UK: Cambridge University Press.
Tsvelev N, 1984. Grasses of the Soviet Union. Part 1. Rotterdam, Netherlands: Balkema, 1-568.
US Fish and Wildlife Service, 2003. In: A Management and Monitoring Plan For Quino Ckeckerspot Butterfly (Euphydryas editha quino) and its Habitats in San Diego County. US Fish and Wildlife Service, 55 pp. http://www.sandiegocounty.gov/pds/mscp/docs/Quino/Quino_mgmt-monitor_Longcore-etc.pdf
US Fish and Wildlife Service, 2008. In: Lange's metalmark butterfly (Apodemia mormo langei) Antioch Dunes evening-primrose (Oenothera deltoides subsp. howellii) Contra Costa wallflower (Erysimum capitatum var. angustatum). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 40 pp.
US Fish and Wildlife Service, 2009. In: Monterey Spineflower (Chorizanthe pungens var. pungens). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 21 pp. http://ecos.fws.gov/docs/five_year_review/doc2393.pdf
US Fish and Wildlife Service, 2010. In: Verbesina dissita (Big-leaved crownbeard). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 38 pp. https://ecos.fws.gov/docs/five_year_review/doc3559.pdf
US Fish and Wildlife Service, 2012. In: Brodiaea pallida (Chinese Camp brodiaea) 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 22 pp. http://ecos.fws.gov/docs/five_year_review/doc4008.pdf
USDA-ARS, 2004. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx
Villarroya M, Escorial MC, Rodrfguez E, Garcfa-Baudfn JM, Chueca MC, 2001. Bromus diandrus population with increased tolerance to metribuzin. The BCPC Conference: Weeds, 2001, Volume 1 and Volume 2. Proceedings of an international conference held at the Brighton Hilton Metropole Hotel, Brighton, UK, 12-15 November 2001, 601-606; 20 ref.
Weiller CM, Henwood MJ, Lenz J, Watson L, 1995. Pooideae (Poaceae) in Australia - Descriptions and Illustrations. Biodiversity and Biological Collections Web Server. http://biodiversity.uno.edu/delta/pooid/www/descr098.htm.
Bor NL, 1960. The Grasses of Burma, Ceylon, India and Pakistan (Excluding Bambusae)., Oxford, UK: Pergamon Press.
CABI, Undated. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
Clayton WD, 1970. Gramineae (Part 1). In: Flora of Tropical East Africa, [ed. by Milne-Redhead E, Polhill RM]. London, UK: Crown Agents for Oversea Governments and Administrations.
Cooper J, Moerkerk M, 2000. Bromus diandrus, Bromus rigidus., Australia: Weed ID/ Management. http://weedman.horsham.net.au/weeds/bromus_spp/bromus.htm
Hoopes M F, Hall L M, 2002. Edaphic factors and competition affect pattern formation and invasion in a California grassland. Ecological Applications. 12 (1), 24-39. DOI:10.1890/1051-0761(2002)012[0024:EFACAP]2.0.CO;2
Royal Botanic Garden Edinburgh, 2004. Flora Europaea Database., Edinburgh, UK: Royal Botanic Garden. http://rbg-web2.rbge.org.uk/FE/fe.html
USDA-ARS, 2004. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx
Weiller C M, Henwood M J, Lenz J, Watson L, 1995. Pooideae (Poaceae) in Australia - Descriptions and Illustrations. In: Pooideae (Poaceae) in Australia - Descriptions and Illustrations, http://muse.bio.cornell.edu/delta/
Distribution MapsTop of page
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