Phalaris paradoxa (awned canary-grass)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Distribution Table
- Habitat List
- Hosts/Species Affected
- Host Plants and Other Plants Affected
- Biology and Ecology
- Impact Summary
- Economic Impact
- Environmental Impact
- 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
- Phalaris paradoxa L.
Preferred Common Name
- awned canary-grass
Other Scientific Names
- Phalaris obvallata Trin.
- Phalaris praemorsa Lam.
- Phalaris pseudoparadoxa Fig. & De Not.
- Phalaris rubens Ehrenb. ex Trin.
- Phalaris sibthorpii Griseb.
International Common Names
- English: annual canarygrass; canarygrass (USA); hood canarygrass (USA); Mediterranean canary grass; paradox canary-grass; paradoxical canary grass
- Spanish: alpiste evanillo; alpiste vano; alpistillo
- French: alpiste paradoxal; phalaris deformé; phalaris rogné
- Portuguese: alpista-brava
Local Common Names
- Australia: bristle-spiked canary grass; paradoxa grass
- Germany: Glanzgras, Seltsames
- Italy: falaride
- Netherlands: kanariegras, vreemd
- PHAPA (Phalaris paradoxa)
Summary of InvasivenessTop of page
P. paradoxa is a tufted annual grass which is considered a weed in many areas and can be invasive. It contains tryptamine alkaloids, which are toxic to some animals. It is native to the Mediterranean region of Europe, but has spread to locations including the USA, Australia and South America. It is a serious weed of wheat in Australia, with its success attribued to high seed production, innate dormancy and periodicity of emergence (Taylor et al., 1999).
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Monocotyledonae
- Order: Cyperales
- Family: Poaceae
- Genus: Phalaris
- Species: Phalaris paradoxa
Notes on Taxonomy and NomenclatureTop of page
The name Phalaris paradoxa is universally accepted for this common weed. Some subspecies have been described: var. paradoxa (common name 'Phalaris deformé' in French) and var. praemorsa (common name 'Phalaris rogné' in French) (Jauzein and Montegut, 1982).
DescriptionTop of page
The following description is taken from the Flora of China Editorial Committee (2016):
Annual, tufted. Culms 15–100 cm tall. Uppermost leaf sheath inflated; leaf blades 2–9 mm wide; ligule 2–8 mm. Panicle dense, narrowly oblong, 4–10 cm, base enclosed in uppermost leaf sheath. Spikelets arranged in clusters composed of 1 fertile spikelet encircled by 6 sterile spikelets, clusters falling entire, sterile spikelets sometimes reduced to club-shaped clusters of glumes. Fertile spikelet: glumes 4.5–6 mm, prominently 7–9-veined, narrowly winged, wing expanded near middle into large tooth, pale green or straw-coloured with dark green stripe above tooth, apex attenuate; sterile lemmas abortive, represented by 2 minute fleshy scales at base of fertile lemma; fertile lemma elliptic, 2.8–3.2 mm, cartilaginous, shiny, sparsely pilose toward apex. Anthers 1–1.8 mm.
DistributionTop of page
P. paradoxa is native to south-west Europe and the Mediterranean (including northern Africa and western Asia) but has spread sporadically across many other regions of the world including northern and central Europe, the USA, Australia, New Zealand, and Uruguay.
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.
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Afghanistan||Widespread||Holm et al., 1991|
|Armenia||Restricted distribution||Fayvush, 2016; USDA-ARS, 2016||Endangered: Yerevan floristic region only|
|China||Present||Present based on regional distribution.|
|-Yunnan||Present||Introduced||1974||Invasive||Flora of China Editorial Committee, 2016|
|India||Present||Holm et al., 1991; Botanical Survey of India, 2016|
|Iran||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Iraq||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Israel||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Lebanon||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Pakistan||Present, few occurrences||Introduced||Flora of Pakistan, 2015||"very rare casual in Pakistan"|
|Qatar||Present||Native||Flora of Qatar, 2016|
|Saudi Arabia||Present||Native||USDA-ARS, 2016|
|Turkey||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Algeria||Widespread||Zitoune-Lameche et al., 1988; USDA-ARS, 2016|
|Egypt||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Ethiopia||Widespread||Holm et al., 1991; Gorfu et al., 1992|
|Morocco||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|-Canary Islands||Present||Native||USDA-ARS, 2016|
|Tunisia||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|USA||Present||Present based on regional distribution.|
|-California||Widespread||Introduced||Robbins et al., 1970; Reed, 1977|
|-Hawaii||Present||Introduced||Reed, 1977; USDA-NRCS, 2016|
|-Louisiana||Present||Introduced||Reed, 1977; USDA-NRCS, 2016|
|-Maryland||Present||Introduced||America Pink, 2016; USDA-NRCS, 2016|
|-New Jersey||Present||Introduced||America Pink, 2016; USDA-NRCS, 2016|
|-Pennsylvania||Present||Introduced||Reed, 1977; USDA-NRCS, 2016|
|-Washington||Present||Introduced||Reed, 1977; USDA-NRCS, 2016|
|Bolivia||Present||Introduced||Missouri Botanical Garden, 2016|
|Chile||Present||Finot and Pedreros, 2012|
|Uruguay||Present||Introduced||Holm et al., 1991; USDA-ARS, 2016|
|Belgium||Present||Introduced||Holm et al., 1991; USDA-ARS, 2016||Adventive|
|Croatia||Present||Native||Tutin, 1980; USDA-ARS, 2016|
|Czech Republic||Present||Introduced||USDA-ARS, 2016|
|France||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Germany||Present||Introduced||Holm et al., 1991; USDA-ARS, 2016|
|Greece||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Italy||Present||Native||Pignati and, 1980; USDA-ARS, 2016|
|Portugal||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Spain||Present||Native||Holm et al., 1991; USDA-ARS, 2016|
|Sweden||Present||Introduced||Holm et al., 1991; USDA-ARS, 2016|
|Switzerland||Present||Introduced||Holm et al., 1991; USDA-ARS, 2016|
|UK||Present||Introduced||Invasive||Holm et al., 1991; Biological Records Centre, 2015||Well established in southern Britain|
|American Samoa||Present, few occurrences||Introduced||Holm et al., 1991|
|Australia||Widespread||Introduced||Holm et al., 1991; Taylor et al., 1999; Weeds of Australia, 2016||Widely naturalized in southern and eastern Australia|
|-Australian Northern Territory||Widespread||Adkins et al., 1997|
|-New South Wales||Present||Introduced||McIntyre et al., 1988; Weeds of Australia, 2016|
|-Queensland||Present||Introduced||Wilson, 1981; Weeds of Australia, 2016||Southern and central areas|
|-South Australia||Present||Introduced||Weeds of Australia, 2016|
|-Tasmania||Present||Introduced||Weeds of Australia, 2016|
|-Victoria||Present||Introduced||Amor, 1985; Weeds of Australia, 2016|
|-Western Australia||Present||Introduced||Weeds of Australia, 2016||Southern and western parts|
|New Zealand||Localised||Introduced||Holm et al., 1991; Edgar and Connor, 2010|
IntroductionsTop of page
|Introduced to||Introduced from||Year||Reason||Introduced by||Established in wild through||References||Notes|
|Natural reproduction||Continuous restocking|
|China||Mexico||1974||Flora of China Editorial Committee (2016)||Introduced in wheat seed imported from Mexico|
|UK||1687||Forage (pathway cause)||Biological Records Centre (2015)||Cultivated in 1687, then recorded as a casual in Surrey by 1859|
HabitatTop of page
Annual Phalaris species usually grow in areas with a rainy, wet winter (subhumid) and in alluvial, sandy-clay or clay texture soils (Jauzien and Montegut, 1982). They are particularly well adapted to winter crops, and are difficult to control in cereal crops. P. paradoxa is predominant in clay soils under rain-fed conditions, and can be well adapted to the lower parts of cropped land where water accumulates and soil moisture content is high (Thurley and Chancellor, 1985; Saavedra et al., 1989; Jimenez et al., 1997). In the UK it is found on tips and waste ground, and as a weed in arable fields and newly sown grass leys (Biological Records Centre, 2015).
Habitat ListTop of page
Hosts/Species AffectedTop of page
A list of crops in which the annual Phalaris spp. (P. paradoxa, P. brachystachys and P. minor) are actual, or potential weed problems would include virtually every annual winter (autumn-sown) crop of temperate regions and every annual summer (spring-sown) crop in colder, subtemperate regions within the geographical range of these species. The list provided includes only those crops where Phalaris species are commonly reported as weed problems. P. paradoxa is most often listed as a weed of cereals (especially wheat), and is the second most prominent annual winter grass weed in the northern grain region of Australia (Taylor et al., 1999).
Host Plants and Other Plants AffectedTop of page
|Beta vulgaris (beetroot)||Chenopodiaceae||Other|
|Brassica napus var. napus (rape)||Brassicaceae||Main|
|Carthamus tinctorius (safflower)||Asteraceae||Other|
|Helianthus annuus (sunflower)||Asteraceae||Main|
|Hordeum vulgare (barley)||Poaceae||Main|
|Papaver somniferum (Opium poppy)||Papaveraceae||Other|
|Pisum sativum (pea)||Fabaceae||Other|
|Triticum aestivum (wheat)||Poaceae||Main|
|Triticum turgidum (durum wheat)||Poaceae||Main|
|Vicia faba (faba bean)||Fabaceae||Main|
Biology and EcologyTop of page
The chromosome number of P. paradoxa is 2n=14 (Talavera, 1987).
In warmer temperate regions Phalaris spp. behave as winter annuals, germinating in the autumn or winter, and reaching reproductive maturity in the following spring. Newly harvested Phalaris seeds exhibit at least 50% germinability. The optimum temperature range for germination is between 8 and 20°C (Jiménez et al., 1997). The percentage of germination is much lower in dark than in light conditions (Jiménez-Hidalgo et al., 1993). Phalaris spp. form a persistent seed bank in the soil and the annual germination and establishment of seedlings has been recorded as between 8 and 11% of the seed bank (Jiménez et al., 1997). Most Phalaris seedlings emerge from shallow depths <3 cm depth in the soil).
Plants are self-incompatible and did not set any seed when heads were bagged (Voshell, 2014).
Physiology and Phenology
Germination and emergence is clearly influenced by rainfall patterns. Phalaris normally shows two emergence periods, the first in the autumn, after the first autumn rains, and the second in the winter coinciding with wet weather conditions (Jiménez et al., 1997).
Seeds become light-sensitive when imbibed in the dark and subsequent exposure to white or red light resulted in the germination of deeply dormant populations. High intensities of white light inhibited germination (Taylor et al., 1999). Where seeds were buried in pots and samples exhumed and germination tested at intervals, no seeds survived for longer than 18 months. Germination of non-dormant and moderately dormant populations was restricted to temperatures in the range 5-18.5°C, with the majority of seed germinating at 13.5°C.
Population Size and Density:
In Australia, P. paradoxa seedlings emerging from a large natural seed bank were counted. Some plots were cultivated in March (autumn) whilst others were left uncultivated. In May (autumn) more seedlings emerged from cultivated plots (2070 m-2) than from undisturbed plots (930 m-2) (Taylor et al. 1999). However, this result was reversed for seedlings emerging in July.
Impact SummaryTop of page
Economic ImpactTop of page
P. paradoxa is an aggressive annual grass weed of winter crops in temperate areas and of early spring-sown crops in colder regions (Western Europe, Western USA). It is also an economically important weed in winter crops in the Mediterranean area. 43% of the winter cereal fields surveyed in southern Spain were infested with Phalaris spp. (Saavedra et al., 1989). In Australia, high infestations of P. paradoxa in winter wheat may result in yield reductions of up to 40% (Dellow and Milne, 1986). It is regarded as the second most prominent winter grass weed in the northern grain region of Australia (Taylor and Taylor, 1999).
P. paradoxa contains tryptamine alkaloids, which are toxic to horses. Ingestion of P. paradoxa plants has been implicated in sporadic plant poisoning cases in horses in Australia (Bourke et al., 2003).
Environmental ImpactTop of page
While primarily a common weed of crops, P, paradoxa is also regarded as an environmental weed in Victoria, Australia (Weeds of Australia, 2016). As an invasive plant in California, USA, it has also been listed with other invasive species as among the threats to the endangered grass Greene’s tuctoria (Tuctoria greenei). This grass species is dependent on vernal pools for survival, and competition from invasive plant species poses a primary threat. P. paradoxa is one of the alien invasive plants typically found along the margins of vernal pools, where T. greenei is also commonly found (US Fish and Wildlife Service, 2007).
Risk and Impact FactorsTop of page Invasiveness
- Proved invasive outside its native range
- Has a broad native range
- Abundant in its native range
- Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
- Pioneering in disturbed areas
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Negatively impacts agriculture
- Threat to/ loss of endangered species
- Threat to/ loss of native species
- Highly likely to be transported internationally accidentally
Similarities to Other Species/ConditionsTop of page
As seedlings, Phalaris species can be distinguished from most other grass weed species. However, confusion may arise between seedlings of Phalaris spp. and Avena spp.. These may be distinguished by the following characteristics: the leaves of Phalaris are glabrous while those of Avena have long hairs at the base of the blade edge; Avena seedlings are darker green than Phalaris; and the base of the seedling stem exhibits a red pigmentation in Phalaris and not in Avena (Jiménez et al., 1997).
Annual Phalaris species with which P. paradoxa is more likely to be confused include:
P. minor (see separate data sheet) - this is similar in vegetative morphology but the glumes lack the marked teeth of P. paradoxa.
P. brachystachys – this has a shorter panicle (3-3.5 cm long, compared with 4-5 cm in P. paradoxa).
Edgecombe (1970) provides useful drawings of the spikelets of P. minor, P. brachystachys and P. paradoxa. When flowering, P. paradoxa can be identified by the clusters of five to seven spikelets of which only the central one is fertile, and by the characteristic marked teeth of the glumes.
Prevention and ControlTop of page
Date of crop sowing
Delaying crop sowing enables the main flush of Phalaris seedlings, which emerge after the first autumn rains, to be controlled before planting. Additionally, in late winter or early spring-sown crops, temperatures are higher, crops grow more quickly, and are more effective at suppressing weed growth. However, crop yields are generally reduced by late spring-sowing.
Increased crop seed sowing rates result in higher crop densities which are able to suppress weed growth. For example, in winter cereals where infestation by Phalaris spp. is often a problem, high seed sowing rates (>170 kg/ha) effectively reduce the density of these weeds. Conversely, low seed rates of wheat or barley (60-80 kg/ha) contribute to a rapid increase in populations of Phalaris spp..
This involves replacing crops in which Phalaris control is difficult or expensive (winter cereals), with other crops with a different growth cycle (e.g. sunflowers), thus avoiding Phalaris infestations, or in which a high degree of control can be achieved (e.g. rapeseed). In the Mediterranean region, Phalaris infestations in winter cereals were greatly reduced by introducing spring-sown sunflower into the rotation.
Mature Phalaris plants at the flowering and seed setting stage are taller than wheat and barley crop plants. Thus, roguing may be practised to reduce or prevent seed return to the soil seed bank. Normally this practice is only feasible when the weed density is low <1500 plants/ha, which may take 3-4 h to hand-rogue). Herbicide-roguing involves the application of a chemical (often glyphosate) to the top of the Phalaris plants with special gloves moistened by a herbicide solution. Chemical roguing is much faster than hand roguing as it does not involve the removal of the plant from the field.
Several herbicides applied pre-emergence or early post-emergence have been used to control Phalaris spp. in winter wheat and other crops. These include isoproturon, methabenzthiazuron, terbutryn and pendimethalin. More recently specialized post-emergence graminicides have been developed and used to control Phalaris spp. (Mirkamali, 1993). Tralkoxydim is effective, fenoxaprop-p-ethyl may be applied in many dicotyledenous crops and in wheat, clodanifop-propargyl is effective in triticale and durum wheat (Welsh and Popay, 1994). Cycloxydim, haloxyfop, fluazifop and sethoxydim are highly selective graminicides that can be used in many broad-leaved crops.
Resistance to herbicides has developed in some P. paradoxa populations. Herbicide Resistant Weeds (2016) reports cases of resistance in Australia, Iran, Israel, Italy and Mexico, mostly in wheat crops to ACCase Inhibitor herbicides.
ReferencesTop of page
Adkins SW; Wills D; Boersma M; Walker SR; Robinson G; McLeod RJ; Einan JP, 1997. Weed resistance to chlorsulfuron and atrazine from the north-east grain region of Australia. Weed Research, 37(5):343-349.
Afentouli CG; Eleftherohorinos IG, 1996. Littleseed canarygrass (Phalaris minor) and short-spiked canarygrass (Phalaris brachystachys) interference in wheat and barley. Weed Science, 44(3):560-565; 24 ref.
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Zitoune-Lameche B; Caussanel JP; Hadj-Miloud D; Barralis G, 1988. Influence of soil tillage and chemical weeding on the relations between weeds and wheat. VIIIe Colloque International sur la Biologie, l'Ecologie et la Systematique des Mauvaises Herbes Paris, France; A.N.P.P., Vol. 2:581-589
ContributorsTop of page
14/06/16 Updated by:
Ian Popay, Landcare Research, New Zealand
Distribution MapsTop of page
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