Brachypodium distachyon
(purple false brome)

Pictures

Picture	Title	Caption	Copyright
Title Habit Caption Brachypodium distachyon (purple false brome); habit. In open red gum forest. nr. Narrandera, New South Wales, Australia. October 2012. Copyright ©Harry Rose-2012/'Macleay Grass Man'/via flickr - CC BY 2.0	Habit	Brachypodium distachyon (purple false brome); habit. In open red gum forest. nr. Narrandera, New South Wales, Australia. October 2012.	©Harry Rose-2012/'Macleay Grass Man'/via flickr - CC BY 2.0
Title Spikelet Caption Brachypodium distachyon (purple false brome); spikelet. Spikelets are slightly flattened, 7-15-flowered and 20–40 mm long. Glumes are shorter than the lemmas. Copyright ©Harry Rose-2012/'Macleay Grass Man'/via flickr - CC BY 2.0	Spikelet	Brachypodium distachyon (purple false brome); spikelet. Spikelets are slightly flattened, 7-15-flowered and 20–40 mm long. Glumes are shorter than the lemmas.	©Harry Rose-2012/'Macleay Grass Man'/via flickr - CC BY 2.0
Title Spikelets Caption Brachypodium distachyon (purple false brome); spikelets. The brome-like spikelets arranged on wheatgrass-like inflorescences are distinctive of this genus. Escondido, California, USA. March 2012. Copyright ©Prof Matt Lavin-2012/Bozeman, Montana, USA - CC BY-SA 2.0	Spikelets	Brachypodium distachyon (purple false brome); spikelets. The brome-like spikelets arranged on wheatgrass-like inflorescences are distinctive of this genus. Escondido, California, USA. March 2012.	©Prof Matt Lavin-2012/Bozeman, Montana, USA - CC BY-SA 2.0
Title Seed heads Caption Brachypodium distachyon (purple false brome); mature seed heads. San Luis Obispo, California, USA. July 2015. Copyright ©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0	Seed heads	Brachypodium distachyon (purple false brome); mature seed heads. San Luis Obispo, California, USA. July 2015.	©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0
Title Habit Caption Brachypodium distachyon (purple false brome); habit, mid summer, showing lodged, dry plants. San Luis Obispo, California, USA. July 2015. Copyright ©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0	Habit	Brachypodium distachyon (purple false brome); habit, mid summer, showing lodged, dry plants. San Luis Obispo, California, USA. July 2015.	©Prof Matt Lavin-2015/Bozeman, Montana, USA - CC BY-SA 2.0

Identity

Preferred Scientific Name

• Brachypodium distachyon (L.) P. Beauv.

Preferred Common Name

• purple false brome

Other Scientific Names

• Bromus distachyos L.
• Trachynia distachya (L.) Link

International Common Names

• English: annual false brome; false brome; purple false brome; stiff-brome

Local Common Names

• China: er sui duan bing cao
• Finland: aroluste
• France: brachypode à deux épis; brachypode de Pau; brachypode de Phénicie; brachypode des bois; cutandie maritime; vulpie genouillée
• Germany: istrianer zwenke; zweiährige zwenke; zweigrannige zwenke
• Sweden: grusskafting

Summary of Invasiveness

B. distachyon, commonly known as purple false brome, is a grass species that is related to the major cereal grain species. It is native to southern Europe, northern Africa and southwestern Asia east to India but is widely introduced and naturalized elsewhere. It occurs broadly as an alien species throughout North America and has been reported as invasive in China, Chile, Australia and California. Brachypodium species are invasive weeds that dominate areas where they are planted or have become established and this species can equally form dense stands, reducing diversity and preventing the establishment of native species. The California Invasive Plant Council (Cal-IPC) classifies its potential impact on native ecosystems as ‘Moderate’.

Taxonomic Tree

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

Notes on Taxonomy and Nomenclature

Brachypodium is a genus of about 18 species. About 15 species, among them Brachypodium distachyon, occur naturally in Eurasia, centered in the Mediterranean. Three species occur in the Western Hemisphere, centered in Mexico (Flora of North America Editorial Committee, 2016).

B. distachyon was first described by A.M.F.J. Palisot de Beauvois in 1812. The phylogenetic status of B. distachyon has been full of controversy. B. distachyon is sometimes treated as the only member of Trachynia Link. However, recently scientists have reclassified it into its own tribe Brachypodieae based upon cytological, anatomical and physiological studies (Hasterok et al., 2004; Flora of North America Editorial Committee, 2016; Gramene, 2016).

The Plant List (2016) includes at least 40 synonyms showing its previous inclusion in the genera Agropyron, Brachypodium, Bromus, Festuca, Secale, Trachynia, Triticum anmd Zerna.

Brachypodium is related to the major cereal grain species. But it is understood to be more closely related to the Triticeae (wheat, barley) than to the other cereals (Gramene, 2016).

Brachy is Greek for "short" and podion is Greek for "little foot". "Short footed" refers to the small pedicels of the spikelets (Watson and Dallwitz, 2016).

Description

B. distachyon is an erect annual grass. Culms geniculately ascending, or decumbent; 3-40 cm long. The following is adapted from Cal-IPC (2016) and Clayton et al. (2016).

Leaves

Bright green or greenish-blue leaves; leaf-sheaths with slightly stiffened distinct hairs ascending from the surface. Ligule an eciliate membrane. Leaf-blades 1–12 cm long; 1–6 mm wide; glaucous. Leaf-blade surface with slightly stiffened distinct hairs ascending from the surface; sparsely hairy.

Inflorescence

Inflorescence composed of racemes. Racemes 1; single; bilateral; 2–8(–10) cm long; bearing 1–7 fertile spikelets on each. Spikelet packing broadside to rhachis. Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong; 0.5–1 mm long.

Fertile spikelets

Spikelets comprising 5–16 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10–30 mm long; breaking up at maturity; disarticulating below each fertile floret.

Glumes

Glumes persistent; dissimilar; shorter than spikelet. Lower glume lanceolate; 5–6 mm long; 0.75 length of upper glume; coriaceous; without keels; 5–7 -veined. Lower glume lateral veins ribbed. Lower glume apex acute. Upper glume oblong; 7–8 mm long; 0.75 length of adjacent fertile lemma; coriaceous; without keels; 7 -veined. Upper glume lateral veins ribbed. Upper glume apex acute.

Florets

Fertile lemma oblong; laterally compressed; 8–10 mm long; coriaceous; glaucous; without keel; 7 -veined. Lemma surface glabrous, or pilose. Lemma margins ciliolate; hairy above. Lemma apex acute; awned; 1 -awned. Principal lemma awn 8–12 mm long overall. Apical sterile florets resembling fertile though underdeveloped.

Flowers

Lodicules 2; ciliate. Anthers 3; 0.5–1 mm long. Ovary pubescent on apex.

Fruits

Caryopsis with adherent pericarp; ellipsoid; hairy at apex, 7-8 mm long. Embryo 0.25 length of caryopsis. Hilum linear; 1 length of caryopsis (Cal-IPC, 2016; Clayton et al., 2016).

Plant Type

Distribution

B. distachyon is native to the Madeira Islands, Canary Islands and northern Africa: Ethiopia; Algeria; Egypt; Libya; Morocco and Tunisia; southwestern Asia east to Pakistan: Azerbaijan; Russian Federation (Dagestan); Turkmenistan; Uzbekistan; Afghanistan; Cyprus; Egypt (Sinai); Iran; Iraq; Israel; Jordan; Lebanon; Syria; Turkey and Pakistan; and east and southern Europe: Ukraine; Albania; Bulgaria; Croatia; Greece; Italy; Slovenia; France; Portugal and Spain. It is uncertain whether it’s native to the Azores, Portugal (DAISIE, 2016; GBIF, 2016; USDA-ARS, 2016).

Others report that B. distachyon is also native to India (Cal-IPC, 2016), Tibet and Tajikistan (Encyclopedia of Life, 2016).

This species is widely introduced and naturalized elsewhere (USDA-ARS, 2016). It occurs broadly as an alien species throughout North America and has specifically been reported from Texas, Colorado, California, Oregon, Hawai’i and New Jersey (USDA-NRCS, 2016). It has been reported as invasive in China, Chile (offshore islands), Australia (New South Wales) (PIER, 2016) and in California, USA (Calflora, 2016).

Distribution Table

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.

Risk of Introduction

The California Invasive Plant Council (Cal-IPC) classifies its potential impact on native ecosystems as ‘Moderate’, meaning that “the species has substantial and apparent, but generally not severe, ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread”. Based on impact, invasiveness and distribution, Cal-IPC (2016) has given B. distachyon the alert status: ‘No Alert’. There is significant risk of introduction of B. distachyon as a contaminant of cereal or grass seeds and carried in wool. Deliberate introduction can also occur when it is used as a research tool.

Habitat

This species is native to dry, open habitats where it grows on sandy or rocky soils. Where it is introduced and naturalized, it is often found in disturbed areas (Flora of North America Editorial Committee, 2016). The Encyclopedia of Life (2016) also mentions forest edges, abandoned plantations, beaches, coastal dunes, orchards and waste places as habitats where B. distachyon can be found.

In California it is reported to invade undisturbed/disturbed grasslands, dry slopes and fields, roadsides, margins of shrub thickets and oak woodlands. It tolerates partial shade in oak woodlands (Cal-IPC, 2016).

In Australia it grows in dry, disturbed areas on sandy or rocky soils (Flora of North America Editorial Committee, 2016).

Habitat List

Biology and Ecology

Genetics

Chromosome number: 5; 2n = 2x = 10, 4x = 20, 6x = 30 polyploidy (Gramene, 2016).

Reproductive Biology

B. distachyon is a winter annual that reproduces only by seed. It has a rapid life cycle, it reaches reproductive maturity within eight to twelve weeks (Li et al., 2012). Bloom period is from April to July. This species is self compatible (Cal-IPC, 2016). Seed longevity in the soil is expected to last two years (DiTomaso et al., 2013). Germination is variable within the species. There may be varying duration of after-ripening requirement and response to light; in general, light tended to reduce germination rather than enhance it (Barrero et al., 2011)..   

Physiology and Phenology

B. disatachyon  has C₃ physiology. Aronson et al. (1992) have compared the dynamics of vegetative and reproductive growth in matched pairs of Mediteranean and desert populations of three unrelated annual species, among them B. distachyon, under high and low levels of water availability in a common-environment experiment. B. distachyon showed earlier switches to reproductive development and to subsequent phenophases, and the transition to flowering occurred at smaller plant sizes. Water stress slightly accelerated the transition to flowering in B. distachyon by 4–6 days. The duration of life cycle was greatly shortened by water stress.

The experiment also showed that the Mediterranean population of B. distachyon was much more plastic in its response to water stress than the desert population in its transition to plant ageing. It appeared that plants from the desert populations were adapted to shorter, more compact growth cycles, culminating in earlier dates of seed maturation and plant ageing. They also showed larger phenotypic plasticity in the transition to plant ageing, which trait was enhanced or magnified by sustained or repeated lack of water. By contrast, plants from Mediterranean populations delayed switchover from one phenophase to the next, seeming to “bet” on more water in the near future (Aronson et al., 1992).

Longevity

B. distachyon is a winter annual but seeds may persist in the soil for at least 2 years (DiTomaso et al., 2013). 

Environmental Requirements

This species tolerates arid environments with annual rainfalls between 279 mm and 1702 mm (Calflora, 2016). According to Cal-IPC (2016), it can be found at elevations up to 600 m. Calflora (2016) reports on altitudes from 4 m up to 950 m.

B. distachyon grows on non-saline soils with a pH of 3.4 to 7.6. It tolerates a very low concentrate of CaCO3 (3%). The grass requires a minimum depth of 20 cm and grows on fine, medium and coarse soil textures (Calflora, 2016).

Climate

Air Temperature

Rainfall

Soil Tolerances

Soil drainage

• free

Soil reaction

• acid
• alkaline
• neutral
• very acid

Soil texture

• heavy
• light
• medium

Means of Movement and Dispersal

Natural Dispersal

This species is spread by water (Cal-IPC, 2016).

Vector Transmission (Biotic)

Florets fall near the plant and can be dispersed by animals (Cal-IPC, 2016).

Accidental Introduction

The florets of B. distachyon can also be dispersed by vehicle tyres and human activities, especially in contaminated hay (Cal-IPC, 2016).

Intentional Introduction

Researchers use this species as a model for the grasses used to produce biomass, food, feed and forage (USDA-JGI, 2016).

Pathway Causes

Pathway Vectors

Impact Summary

Environmental Impact

It occurs broadly as an alien species throughout North America and has been reported as invasive in China, Chile, Australia and California (Calflora, 2016; PIER, 2016).

Brachypodium genera are invasive weeds that dominate areas where they grow (USDA Forest Service, 2003). In the USA, B. distachyon is a weed of urban bushland and of the western edge of the wheatbelt. It is specifically reported from California, Oregon, Texas, Colorado, Hawaii and New Jersey. Generally, it is under-reported, probably because of superficial similarity to Bromus species (Hussey et al, 1997; Gramene, 2016). B. distachyon is locally abundant in California. It seems to still be spreading in California, but probably at a relatively slow rate statewide. Regionally it can spread rapidly (Cal-IPC, 2016).

Impact on Habitats

B. distachyon can form dense stands that can change fire regimes and build up thick litter layers (Cal-IPC, 2016). An increase in woody vegetation and nonnative plant species in some habitats has resulted in less available prairie habitat overall.

Impact on Biodiversity

Cal-IPC (2016) evaluated the impact of B. distachyon on plant community composition, structure, and interactions as ‘Moderate’. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread. It can form dense stands in some locations, particularly in oak woodlands. These near monotypic stands can reduce diversity and prevent native species from establishing. The impact on higher trophic levels is evaluated as ‘Moderate’. The fibrous stems make it a poor forage for animals. The long awns can also injure animals (Cal-IPC, 2016).

It is recorded, among others, as being one of the most prominent nonnative species threatening the endangered Acanthomintha ilicifolia, competing for nutrients, light, water and space (US Fish and Wildlife Service, 2009). It is also noted as an invasive of concern to the protection of the endangered species Sibara filifolia (US Fish and Wildlife Service, 2006).  

B. distachyon can contribute to the loss of prairie habitat, and subsequently lead to habitat that is avoided by some butterflies and birds, such as the Taylor’s checkerspot butterflies (Euphydryas editha taylori) and streaked horned larks (Eremophila alpestris strigata) (US Fish and Wildlife Service, 2013).

Based on impact, invasiveness and distribution, Cal-IPC (2016) has given B. distachyon the alert status: ‘No Alert’.

Threatened Species

Risk and Impact Factors

• Proved invasive outside its native range
• Has a broad native range
• Pioneering in disturbed areas
• Tolerant of shade
• Fast growing

• Ecosystem change/ habitat alteration
• Modification of fire regime
• Modification of successional patterns
• Monoculture formation
• Reduced native biodiversity
• Threat to/ loss of native species

• Competition - monopolizing resources
• Competition - smothering
• Predation

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

Uses

Economic Value

B. distachyon is used by researchers as a model for the grasses used to produce biomass, food, feed and forage. The species has many qualities that make it an excellent model organism for functional genomics research in temperate grasses, cereals, and dedicated biofuel crops. These attributes include the relatively small size of its genome which makes it useful for genetic mapping and sequencing. It has diploid accessions and a series of polyploid accessions. It is small sized, has a short lifecycle and it is self compatible. As a weed it has simple growth requirements (USDA-JGI, 2016).

Studies in B. distachyon have provided new insight into the structure and physiology of plant cell walls, the development and chemical composition of endosperm, and the genetic basis for cold tolerance. Recent work on auxin transport has also uncovered mechanisms that apply to all angiosperms other than Arabidopsis (Kellogg, 2015).

The species is a poor forage grass for livestock (DiTomaso et al., 2013).

Uses List

General

• Research model

Similarities to Other Species/Conditions

B. distachyon can be distinguished from other species of Brachypodium by having shorter pedicels and anthers, laterally compressed spikelets, and fewer spikelets per raceme. This species is the only annual member of the Brachypodieae and its flowers are self-pollinating and set fertile seed without the flower opening (Flora of North America Editorial Committee, 2016; Gramene, 2016). In the UK it is distinguished from native Brachypodium species by its annual habit (Stace, 1991).

It can be confused with Bromus hordeaceus (soft brome), an annual grass which is hairy all over, and has rounder, hairier, softer seedheads (Cal-IPC, 2016).

Prevention and Control

Cultural Control and Sanitary Measures

Prescribed burning in early summer has successfully reduced the size of populations. It is a poor forage grass and so grazing is unlikely to be a useful control measure (DiTomaso et al., 2013).

Physical/Mechanical Control

Hand pulling, mowing or tillage may be suitable for small infestations. Mowing should be undertaken before viable seed production but after most of the soil moisture has been depleted to prevent regrowth (DiTomaso et al., 2013).

Chemical Control

In California B. distachyon has reportedly been controlled by the grass-specific herbicide fluazifop-p-butyl and by the non-selective glyphosate (Conservation Biology Institute, 2016). No other specific chemicals are reported, although it is likely that similar herbicides used to control other grasses may be relevant for this species (DiTomaso et al., 2013). In Israel it is reported to be resistant to triazine herbicides (Regev and Kleifeld, 1982).

References

Aronson J, Kigel J, Shmida A, Klein J, 1992. Adaptive phenology of desert and Mediterranean populations of annual plants grown with and without water stress. Oecologia, 89(1):17-26.

Barrero JM, Jacobsen JV, Talbot MJ, White RG, Swain SM, Garvin DF, Gubler F, 2011. Grain dormancy and light quality effects on germination in the model grass Brachypodium distachyon. New Phytologist, 193(2):376-386.

Calflora, 2016. Information on California plants for education, research, and conservation. Berkeley, California, USA: Calflora Database. http://www.calflora.org

Cal-IPC (California Invasive Plant Council), 2016. California Invasive Plants Council. Berkeley, California, USA: California Invasive Plant Council. http://www.cal-ipc.org/

Clayton WD, Vorontsova MS, Harman KT, Williamson H, 2016. GrassBase - The Online World Grass Flora. http://www.kew.org/data/grasses-db.html

Conservation Biology Institute, 2016. Brachypodium Control: Experimental Treatments to Control Brachypodium - An Adaptive Approach for Conserving Endemic Species, San Diego County, California. California, USA: Conservation Biology Institute. http://consbio.org/products/reports/brachypodium-control

DAISIE, 2016. Delivering Alien Invasive Species Inventories for Europe. European Invasive Alien Species Gateway. www.europe-aliens.org/default.do

DiTomaso JM, Kyser GB, Oneto SR, Wilson RG, Orloff SB, Anderson LW, Wright SD, Roncoroni JA, Miller TL, Prather TS, Ransom C, Beck KG, Duncan C, Wilson KA, Mann JJ, 2013. Weed Control in Natural Areas in the Western United States. Davis, California, USA: Weed Research and Information Center, University of California, 544 pp.

Encyclopedia of Life, 2016. Encyclopedia of Life. http://www.eol.org

Flora of North America Editorial Committee, 2016. Flora of North America North of Mexico. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.efloras.org/flora_page.aspx?flora_id=1

GBIF, 2016. Global Biodiversity Information Facility. http://www.gbif.org/species

Gramene, 2016. The Gramene database. Release #39. http://www.gramene.org/

Hasterok R, Draper J, Jenkins G, 2004. Laying the cytotaxonomic foundations of a new model grass, Brachypodium distachyon (L.) Beauv. Chromosome Research, 12(4):397-403.

Hussey BMJ, Keighery GJ, Cousens RD, Dodd J, Lloyd SG, 1997. Western weeds. A guide to the weeds of Western Australia. Western weeds. A guide to the weeds of Western Australia., ii + 254 pp.

ITIS, 2016. Integrated Taxonomic Information System online database. http://www.itis.gov

Kaye T, 2003. Invasive Plant Alert False-brome (Brachypodium sylvaticum). Oregon, USA: Institute for Applied Ecology, 2 pp. http://appliedeco.org/wp-content/uploads/brsybrochure.pdf

Kellogg EA, 2015. Brachypodium distachyon as a genetic model system. Annual Review of Genetics, 49:1-20. http://www.annualreviews.org/doi/full/10.1146/annurev-genet-112414-055135

Li ChuAn, Rudi H, Stockinger EJ, Cheng HongMei, Cao Moju, Fox SE, Mockler TC, Westereng B, Fjellheim S, Rognli OA, Sandve SR, 2012. Comparative analyses reveal potential uses of Brachypodium distachyon as a model for cold stress responses in temperate grasses. BMC Plant Biology, 12(65):(8 May 2012). http://www.biomedcentral.com/content/pdf/1471-2229-12-65.pdf

PIER, 2016. Pacific Island Ecosystems at Risk. Honolulu, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

Regev Y, Kleifeld Y, 1982. A triazine-resistant weed -- is it a sign of a new problem? Hassadeh, 62(12):2284-2286.

Stace C, 1991. New Flora of the British Isles [ed. by Cambridge University Press]. Cambridge, UK: Cambridge University Press.

The Plant List, 2013. The Plant List: a working list of all plant species. Version 1.1. London, UK: Royal Botanic Gardens, Kew. http://www.theplantlist.org

US Fish and Wildlife Service, 2006. 5-Year Review: Summary and Evaluation: Species Reviewed: Sibara filifolia. California, USA: US Fish and Wildlife Service.

US Fish and Wildlife Service, 2006. In: Sibara filifolia (Santa Cruz Island Rockcress). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 24 pp..

US Fish and Wildlife Service, 2009. 5-Year Review: Summary and Evaluation: Species Reviewed: Acanthomintha ilicifolia. California, USA: US Fish and Wildlife Service.

US Fish and Wildlife Service, 2009. In: Acanthomintha ilicifolia (San Diego thornmint). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 39 pp.. http://ecos.fws.gov/docs/five_year_review/doc2571.pdf

US Fish and Wildlife Service, 2013. Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for the Taylor's Checkerspot Butterfly and Threatened Status for the Streaked Horned Lark. Federal Register, 78(192). Washington DC, USA: Department of the Interior, 53.

USDA-ARS, 2016. Germplasm Resources Information Network (GRIN). National Plant Germplasm System. Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx

USDA-JGI, 2016. Brachypodium genome resources project. Joint Genome Institute. Berkeley, USA: Joint Genome Institute, Lawrence Berkeley National Laboratory.

USDA-NRCS, 2016. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/

Watson L, Dallwitz MJ, 2016. The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Institute of Botany, Chinese Academy of Sciences. http://delta-intkey.com

Contributors

02/03/16 Original text by: 

Diana Quiroz, Naturalis Biodiversity Center, Netherlands

Distribution Maps