Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Glyceria maxima
(reed sweet-grass)

Toolbox

Datasheet

Glyceria maxima (reed sweet-grass)

Summary

  • Last modified
  • 20 November 2018
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Glyceria maxima
  • Preferred Common Name
  • reed sweet-grass
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Monocotyledonae
  • Summary of Invasiveness
  • G. maxima is an aquatic, perennial grass, which is native to temperate Europe and Asia, and an invasive species in New Zealand, Australia and North America (

  • There are no pictures available for this datasheet

    If you can supply pictures for this datasheet please contact:

    Compendia
    CAB International
    Wallingford
    Oxfordshire
    OX10 8DE
    UK
    compend@cabi.org
  • Distribution map More information

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report

Pictures

Top of page
PictureTitleCaptionCopyright

Identity

Top of page

Preferred Scientific Name

  • Glyceria maxima (Hartman) Holmburg, 1919

Preferred Common Name

  • reed sweet-grass

Other Scientific Names

  • Glyceria aquatica (L.) Wahlberg, 1820
  • Glyceria spectabilis Mert. & W. D. J. Koch
  • Molinia maxima Hartman, 1820
  • Panicularia aquatica (L.) Kuntze
  • Poa aquatica Linnaeus, 1753

Local Common Names

  • : reed mannagrass; swamp grass; water meadow grass; water sweet-grass

Summary of Invasiveness

Top of page

G. maxima is an aquatic, perennial grass, which is native to temperate Europe and Asia, and an invasive species in New Zealand, Australia and North America (USDA-ARS, 2009). In the USA, it is listed as prohibited in Massachusetts and potentially invasive in Connecticut (USDA-NRCS, 2009).

G. maxima spreads vigorously from rhizomes and seedlings that produce numerous vegetative and flowering shoots. A single plant may produce up to 100 shoots and 30 m of rhizome in its first 2 years of growth (Parsons and Cuthbertson, 1992).

Dense stands of G. maxima severely impede water flow in canals and streams, often causing local flooding and livestock to become bogged down and drown (Bartonet al., 1983). It also causes accelerated siltation resulting in a reduction of the holding capacity of farm dams (Parsons and Cuthbertson, 1992). The ability of this vigorous invader to create monocultures is of conservation concern even in its native range (Lambert, 1947).

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Monocotyledonae
  •                     Order: Cyperales
  •                         Family: Poaceae
  •                             Genus: Glyceria
  •                                 Species: Glyceria maxima

Notes on Taxonomy and Nomenclature

Top of page

Glyercia is from the Greek glykeros, meaning ‘sweet’, and refers to the sweet taste of seeds from some species. Maxima is the superlative of the Latin magnus, meaning ‘great’ or ‘large’, inferring that this species is the largest in the genus (Parsons and Cuthbertson, 1992). A cultivar G. maxima 'Variegata' is grown in <_st13a_place _w3a_st="on">North America.

Description

Top of page

G. maxima is a robust, leafy, aquatic, perennial grass that grows 90-250 cm high, with numerous vegetative shoots. Seeds germinate in spring and seedlings develop rapidly producing many vigorous shoots as well as a mat of creeping rhizomes in summer and autumn that contribute to spread beyond their periphery. During winter growth slows or ceases and then recommences in spring when both vegetative and flowering shoots are formed.

Leaves glabrous, bright green, sometimes tinged with red when young, especially in the sheath. Sheaths predominantly cross-veined, distinctly keeled distally and broadly naviculate in cross section. Ligule membranous, 3-6 mm long, entire or slightly divided, truncate, but usually with a central point. Blade abruptly pointed, 30-60 cm long, 7-20 mm wide, rough on the margins and sometimes the lower surface.

Inflorescence a loose, later dense, oblong many branched panicle, 15-45 cm long. Spikelets yellow or green tinged with purple, slightly compressed, stalked, oblong, 5-12 mm long, 2-3.5 mm wide and 4 to 10 flowered.

Seed dark brown, 1.5-2 mm long, enclosed in persistent, hardened flowering glumes. Glumes unequal, lower 2-3 mm, upper 3-4 mm, membranous, usually obtuse. Lemmas 3-4 mm long, not keeled, but with usually seven very prominent nerves. Paleas equal to lemmas or slightly shorter, boat shaped, flanges scaberulous. Lodicules fairly large, more or less connate, though generally separable. Stamens 3, anthers up to 2 mm long, yellow or purple. Styles 2, appearing to arise laterally; naked proximally, branched distally.

Root fibrous, 1-2 mm diameter, several arising from each rhizome node, extending to depths of 1 m and giving raise to laterals 1-8 cm long (Lambert, 1947; Parsons and Cuthbertson, 1992).

Plant Type

Top of page Aquatic
Grass / sedge
Perennial
Seed propagated
Vegetatively propagated

Distribution

Top of page

G. maxima is native to the north temperate zone of Europe and <_st13a_place _w3a_st="on">Asia. It is found as far eastward in Asia as <_st13a_country-region _w3a_st="on">Japan and the <_st13a_placename _w3a_st="on"><_st13a_place _w3a_st="on">Kamchatka<_st13a_placetype _w3a_st="on">Peninsula(Anderson and Reznicek, 1994;USDA-ARS, 2009). Several references (DPIWE, 2009; ISSG, 2009) cite that G. maxima is invasive in the <_st13a_country-region _w3a_st="on">UK; however, Lambert (1947) claims that it is native flora of the <_st13a_country-region _w3a_st="on"><_st13a_place _w3a_st="on">UK. Additionally, Stace et al. (2009) states G. maxima is “common in most of England except North, scattered in Wales, Ireland and Scotland, 1 record in Guernsey, not in North or Northwest Scotland.”

Distribution Table

Top 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/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

ChinaPresentPresent based on regional distribution.
-XinjiangPresentNativeFlora of China Editorial Committee, 2006
JapanPresentNativeAnderson and Reznicek, 1994
KazakhstanPresentNativeFlora of China Editorial Committee, 2006
TurkeyPresentNativeDavis, 1965-1988

North America

CanadaPresentPresent based on regional distribution.
-British ColumbiaPresentIntroducedBrouillet et al., 2006; USDA-NRCS, 2009
-Newfoundland and LabradorPresentIntroducedBrouillet et al., 2006; USDA-NRCS, 2009
-OntarioPresentIntroduced1940 Invasive Brouillet et al., 2006; USDA-NRCS, 2009
-QuebecPresentIntroducedBrouillet et al., 2006; USDA-NRCS, 2009
USAPresentPresent based on regional distribution.
-AlaskaWidespreadIntroduced Invasive USDA-NRCS, 2009
-MassachusettsPresentIntroduced1990 Invasive Anderson and Reznicek, 1994
-WisconsinLocalisedIntroduced1975 Invasive Reed, 1987; Anderson and Reznicek, 1994Localized in the southeast corner of Wisconsin

Europe

AustriaPresentNativeUSDA-ARS, 2009
BelarusPresentNativeUSDA-ARS, 2009
BelgiumPresentNativeUSDA-ARS, 2009
BulgariaPresentNativeUSDA-ARS, 2009
Czechoslovakia (former)PresentNativeUSDA-ARS, 2009
DenmarkPresentNativeUSDA-ARS, 2009
EstoniaPresentNativeUSDA-ARS, 2009
FinlandPresentNativeUSDA-ARS, 2009
FrancePresentNativeUSDA-ARS, 2009
GermanyPresentNativeUSDA-ARS, 2009
GreecePresentNativeUSDA-ARS, 2009
HungaryPresentNativeUSDA-ARS, 2009
IrelandPresentNativeUSDA-ARS, 2009
ItalyWidespreadNativeFlora Italiana, 2009Widespread, except the southwest corner
LatviaPresentNativeUSDA-ARS, 2009
LithuaniaPresentNativeUSDA-ARS, 2009
MoldovaPresentNativeUSDA-ARS, 2009
NetherlandsPresentNativeUSDA-ARS, 2009
NorwayPresentNativeUSDA-ARS, 2009
PolandPresentNativeUSDA-ARS, 2009
RomaniaPresentNativeUSDA-ARS, 2009
Russian FederationPresentNativeUSDA-ARS, 2009
-Western SiberiaPresentNative Not invasive Anderson and Reznicek, 1994Kamchatka Peninsula
SwedenPresentLarson, 2003Native to parts of Sweden but also occurs in areas where it is non-indigenous
SwitzerlandPresentNativeUSDA-ARS, 2009
UKPresentNativeUSDA-ARS, 2009
UkrainePresentNativeUSDA-ARS, 2009
Yugoslavia (former)PresentNativeUSDA-ARS, 2009

Oceania

AustraliaPresentPresent based on regional distribution.
-Australian Northern TerritoryAbsent, formerly presentIntroduced Not invasive Brown, 1929A limited number of planting experiments proved unsuccessful
-New South WalesLocalisedIntroduced Invasive Parsons and Cuthbertson, 1992South western slopes of the Great Diving Range and irrigation districts
-QueenslandPresentIntroducedCPBA, 2009
-South AustraliaLocalisedIntroduced Invasive Parsons and Cuthbertson, 1992Mount Lofty Ranges and the southeastern districts
-TasmaniaPresentParsons and Cuthbertson, 1992Agricultural regions, especially in the north of the state
-VictoriaLocalised1900sIntroduced Invasive Parsons and Cuthbertson, 1992Found in Gippsland, the northern region (especially irrigation areas) and the Western Districts
-Western AustraliaLocalisedIntroduced Invasive Western Australian Herbarium, 2009Established in the southwest corner of the state
New ZealandWidespreadIntroduced1904 Invasive Allan, 1940Established in various locations (notably Otago and Southland) on both the North and South Islands
Papua New GuineaAbsent, formerly presentIntroduced Not invasive Brown, 1929A limited number of planting experiments proved unsuccessful

History of Introduction and Spread

Top of page

G. maxima was widely distributed on a commercial scale in Australasia by rootstock planting in the early twentieth century (Lambert, 1947). Allan (1940) gives 1904 as the date of the first printed records of its occurrence in New Zealand. Commercial planting saw G. maxima establish in various locations (notably Otago and Southland) on both the North and South Islands, where it spread sufficiently to block waterways (Allan, 1940). The original source of G. maxima in Australia was a few plants in Victoria grown from English seed. It rapidly became established in Victoria, New South Wales, Tasmania and Western Australia where it proved vigorous enough to out-compete indigenous swamp vegetation in suitable habitats (Brown, 1929). It was later recorded in Queensland (CPBA, 2009). A limited number of planting experiments made in tropical Australia and New Guinea proved unsuccessful (Brown, 1929).

Introduced from Australia to a few places in South Africa, but limited planting experiments have indicated that G. maxima does not flourish or spread nearly as rapidly as reported for Australia, the results being insufficient to warrant further trials (Lambert, 1947).

The first occurrence of G. maxima in North America dates from 1940 and comes from a marsh at the edge of Lake Ontario. Between 1940 and 1952 several more populations of this plant were located in the same region, but it is possible that G. maxima arrived some time before these records were documented. The first record of G. maxima in New England is from the Ipswich River Wildlife Sanctuary in Essex County, Massachusetts in 1990 (IPANE, 2009). In North America, it is now found in southern Canada, primarily in Ontario, but also Newfoundland, British Colombia, and in the USA in Alaska, Wisconsin and Massachusetts (Dore, 1947; Reed, 1987; USDA-NRCS, 2009).

Introductions

Top of page
Introduced toIntroduced fromYearReasonIntroduced byEstablished in wild throughReferencesNotes
Natural reproductionContinuous restocking
Alaska >1940 Yes IPANE (Invasive Plant Atlas of New England) (2009)
British Columbia >1940 Yes IPANE (Invasive Plant Atlas of New England) (2009)
Massachusetts 1990 Yes IPANE (Invasive Plant Atlas of New England) (2009)
New South Wales Victoria <1929 Crop production (pathway cause) Yes Brown (1929)
New Zealand 1904 Crop production (pathway cause) Yes Allan (1940)
Newfoundland and Labrador >1940 Yes IPANE (Invasive Plant Atlas of New England) (2009)
Ontario 1940 Yes IPANE (Invasive Plant Atlas of New England) (2009)
Quebec >1940 Yes IPANE (Invasive Plant Atlas of New England) (2009)
Queensland   Yes CPBA (2009)
South Australia Victoria <1929 Crop production (pathway cause) Yes Brown (1929)
Tasmania Victoria <1929 Crop production (pathway cause) Yes Brown (1929)
Victoria England and Wales early 1900s Crop production (pathway cause) Yes Brown (1929)
Western Australia <1929 Crop production (pathway cause) Yes Brown (1929)
Wisconsin >1940 Yes IPANE (Invasive Plant Atlas of New England) (2009)

Risk of Introduction

Top of page

In Australia, all wetlands, shallow water bodies and the edges of rivers and creeks along the south-eastern coast and south-western corner of Australia have the potential to be invaded wherever the characteristics of the site are suitable (Loo et al., 2009a). In the USA, G. maxima is not currently present in Connecticut, but it is listed as ‘potentially invasive’.

However, dispersal pathways and vectors must be present to spread G. maxima into new regions where habitat is potentially suitable and it is difficult to estimate the time needed for this to occur. Deliberate introductions of the plant as a fodder are still possible, and accidental movement on machinery and animal hooves is a possibility. Seeds are available by mail order from the native range (Seeds-by-size, 2009). Both nursery stock and seeds for sowing are permitted into Australia (AQIS, 2009).

Habitat

Top of page

Wet or occasionally winter-flooded freshwater areas along banks of slow-moving rivers, creeks, canals, drainage ditches, lakes, wetlands, ponds and farm dams, principally in temperate regions. It grows well in water up to 75 cm deep and satisfactorily even at depths of 1.5 m. In deeper water it often forms floating mats which remain attached to the banks of streams or ponds (Parsons and Cuthbertson, 1992).

In its native range, G. maxima is found growing from the lowlands up to high altitudes in the mountain areas (Peeters, 2005). Lambert (1947) suggests that “these plants are typically a freshwater species and found in the bank of slow-flowing rivers. Exhibits a considerable vertical range in relation to water level, occur vigorously both as a reed swamp plant with roots and rhizomes immersed throughout the year. However, the presence of higher internal concentration of oxygen in the roots suggests for an immediate diphenylamine tests made on soil samples containing root fragments. Reaches best development both vegetatively and in production of flowering stems, in regions where summer water table is approximately at substrate level. When growing among other tall reed swamp species, they may produce excessively long vegetative stems. At the same time they are largely limited or excluded by the mechanical conditions of the habitat, where a diurnal tidal rise and fall of 20-30cm is combined with a loose, shifting substrate. These plants are found in fully exposed situations but are tolerant to slight shade”.

Habitat List

Top of page
CategorySub-CategoryHabitatPresenceStatus
Terrestrial
 
Terrestrial – ManagedCultivated / agricultural land Principal habitat Harmful (pest or invasive)
Cultivated / agricultural land Principal habitat Natural
Cultivated / agricultural land Principal habitat Productive/non-natural
Terrestrial ‑ Natural / Semi-naturalRiverbanks Principal habitat Harmful (pest or invasive)
Riverbanks Principal habitat Natural
Riverbanks Principal habitat Productive/non-natural
Wetlands Principal habitat Harmful (pest or invasive)
Wetlands Principal habitat Natural
Wetlands Principal habitat Productive/non-natural
Freshwater
 
Irrigation channels Principal habitat Harmful (pest or invasive)
Irrigation channels Principal habitat Natural
Irrigation channels Principal habitat Productive/non-natural
Lakes Principal habitat Harmful (pest or invasive)
Lakes Principal habitat Natural
Lakes Principal habitat Productive/non-natural
Reservoirs Principal habitat Harmful (pest or invasive)
Reservoirs Principal habitat Natural
Reservoirs Principal habitat Productive/non-natural
Rivers / streams Principal habitat Harmful (pest or invasive)
Rivers / streams Principal habitat Natural
Rivers / streams Principal habitat Productive/non-natural
Ponds Principal habitat Harmful (pest or invasive)
Ponds Principal habitat Natural
Ponds Principal habitat Productive/non-natural

Biology and Ecology

Top of page

Genetics

Chromosome number: 2n=60 (Missouri Botanical Garden, 2010). A cultivar G. maxima 'Variegata' is grown in North America.

Reproductive Biology

Reproduces by seed and rhizomes. Seeds germinate in spring and seedlings develop rapidly producing many vigorous shoots. Seeds are produced in the plants second and subsequent years. Flowering occurs in spring and summer and vast amounts of seeds are produced. These seeds have varying levels of dormancy, with the majority of seeds able to germinate immediately, whilst others are genetically bound to remain dormant for several years (Parsons and Cuthbertson, 1992; DPIWE, 2009). Only 1-9% of the florets set good grains (Dore, 1953 in Anderson and Reznicek, 1994) and the dense cover of the matted weed also hinders the establishment of seedlings (Weiss and Iaconis, 2000).

A mat of creeping rhizomes spreads in summer and autumn. During winter growth slows or ceases and then recommences in spring when both vegetative and flowering shoots are formed. A single plant may produce up to 100 shoots and 30 m of rhizome in its first 2 years of growth. The extensive root system of G. maxima can extend to depths of 1 m. A sprawling mass of rhizomes comprise 40-55% of the plant’s total biomass. These rhizomes produce vast numbers of shoots to quickly expand the plants size (DPIWE, 2002). Plants in mature stands grow considerably slower and those in deep water, with a more anaerobic substrate, grow even more slowly and have reduced rhizome development (Parsons and Cuthbertson, 1992). 

In a mesocosm experiment by Tanner (1996) it was found that shooting density increased linearly during the first 90 days of the trial, then rose sharply during the remaining 30 days of the trial, more than doubling the shoot number. A very high above-ground biomass production (3.3 kg m-2 ) was also found.
 
Associations

Buttery and Lambert (1964) examined the competition between G. maxima and Phragmites communis in the Surlingham Broad, England, UK. They found that where G. maxima shows maximum growth, P. communis is completely suppressed. The success of G. maxima over P. communis under such conditions appears to be due to its rapid production of an extremely dense sward in spring, before the P. communis shoots can develop. However, at the back of the fen away from the open water, P. communis was more successful than G. maxima, indicating that it has somewhat greater tolerance to the unfavourable habitat conditions.

Environmental Requirements

G. maxima is tolerant of waterlogging, fire and frost and of a wide range of climatic conditions, but prefers cooler, temperate regions (Weiss and Iaconis, 2000). It can establish in minor disturbed ecosystems of permanent and seasonal wetlands.

Haslam (1978) states the nutrient requirements (p.p.m.) of G. maxima are:

Calcium: 100-150
Chloride: 40-60
Magnesium: 10-20
Nitrate-nitrogen: Poorly correlated
Ammonia-nitrogen: Poorly correlated
Phosphate-phosphorus: Below 1
Potassium: 20-40
Sodium: 40-60
Sulphate-sulphur: 80+

G. maxima is more likely to be found on soils high in total phosphorus and nitrogen (Loo et al., 2009a). Haslam (1978) found that the grass was phosphorus limited, so it will spread only into areas with adequate phosphorus levels. G. maxima is only tolerant of light shade (Lambert, 1947; Loo et al., 2009b).

Climate

Top of page
ClimateStatusDescriptionRemark
Cs - Warm temperate climate with dry summer Preferred Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers
Ds - Continental climate with dry summer Preferred Continental climate with dry summer (Warm average temp. > 10°C, coldest month < 0°C, dry summers)

Latitude/Altitude Ranges

Top of page
Latitude North (°N)Latitude South (°S)Altitude Lower (m)Altitude Upper (m)
66 46.7

Soil Tolerances

Top of page

Soil drainage

  • seasonally waterlogged

Soil texture

  • heavy
  • light
  • medium

Means of Movement and Dispersal

Top of page

Natural Dispersal (Non-Biotic)

Existing colonies use their creeping rhizomes to spread beyond their periphery. Other dispersal mechanisms are by seed moved in flowing water or vegetative shoot movement during flood events. G. maxima seed is not readily dispersed by wind (Parsons and Cuthbertson, 1992; DPIWE, 2009).

Vector Transmission (Biotic)

Seeds may be moved in mud or on animal fur or hooves, on footwear, machinery or other vehicles (Parsons and Cuthbertson, 1992).

Intentional Introduction

G. maxima was widely distributed on a commercial scale in Australasia by rootstock planting in the early twentieth century (Lambert, 1947).

Pathway Causes

Top of page
CauseNotesLong DistanceLocalReferences
Crop production Yes Yes LAMBERT, 1947
Flooding and other natural disastersMoved in flowing water Yes Yes Parsons and Cuthbertson, 1992
Interconnected waterwaysMoved in flowing water Yes Yes Parsons and Cuthbertson, 1992
Internet sales Yes eBay, 2009; Seeds-by-size, 2009
Nursery tradeSeedlings sold in Victoria in the 1940s Yes Yes Gippsland and Northern Co-operative CoLtd, 1940
Seed tradeSeed sold in Victoria in the 1940s Yes Yes Gippsland and Northern Co-operative CoLtd, 1940

Impact Summary

Top of page
CategoryImpact
Economic/livelihood Positive and negative
Environment (generally) Positive and negative
Human health Negative

Economic Impact

Top of page

In its natural range G. maxima can be readily consumed by cattle and is considered a nutritious fodder. However, in southeastern Australia and New Zealand it accumulates toxic levels of hydrocyanic acid which has resulted in the cyanide poisoning of livestock (Barton, 1983; Parsons and Cuthbertson, 1992). In South Gippsland both beef and dairy cattle deaths in spring have been attributed to G. maxima. Cyanic compounds are highly present in the vegetative tillers of the plant, only slightly in the flowering culms and not in the seeds (Barton, 1983). Additionally, Sharman (1968; cited in Barton 1983) found that the cyanide content of G. maxima varied greatly with season, peaking in spring when the grass was growing fastest and rising again in autumn. Given that G. maxima is not a preferred fodder source in Australasia, infestations result in a loss of area for nutritious fodder. Livestock have also become bogged down and drowned when attempting to reach water through dense infestations (Melbourne Water, 2003).

G. maxima can adversely affect water quality by making the water putrid and unusable. Farmers have had to relocate pumps after infested springs become polluted and cattle refuse to drink the water (Melbourne Water, 2003).The holding capacity of farm dams can be significantly reduced due to siltation. In dense stands it severely impedes water flow in canals, drainage ditches and streams, often causing local flooding (Parsons and Cuthbertson, 1992). There can be significant costs to landholders and waterway managers trying to control G. maxima using either chemical control or mechanical removal.

Environmental Impact

Top of page

Impact on Habitats

G. maxima has been likened to an autogenic ecosystem engineer, with the ability to impede water flow and convert fast-flowing aerobic streams into partially anaerobic swamps (Clarke et al., 2004). The formation of thick rhizomatous root mats is the likely mechanism by which G. maxima traps sediments and alters the stream habitat (Sanity and Jacob, 1994). Dense stands of G. maxima severely obstruct water flow in canals, drainage ditches and streams, often causing local flooding (Parsons and Cuthbertson, 1992). Hence, aquatic ecosystem function, including sediment and organic matter retention and nutrient dynamics, may be drastically affected (Clarke et al., 2004).

Impact on Biodiversity

The ability of this vigorous invader to create monocultures is of conservation concern even in its native range (Lambert, 1947). The spread of G. maxima in England, UK, reduced the number of seed-producing plants (particularly of the Cyperaceae and Polygonaceae) available to winter feeding ducks. G. maxima is reported to be a poor food plant for grazing waterfowl and a poor nesting substrate for many common wetland species (Burgess et al., 1990). Native to parts of Sweden but also occurs in areas where it is non-indigenous. In its introduced range it is seen to form dense stands which impact on native vegetation (Larson, 2003).

Impacts of G. maxima on native biota and ecosystems in the invaded range are poorly explored, but Clarke et al., (2004) found that streams invaded by G. maxima in S. Australia had lower compositional diversity of stream macroinvertebrates, with a shift from ‘shredders’ to ‘collector/filterers’.

In New Zealand, Taylor and Kelly (2001) found that G. maxima is proving to be a national threat to the whitebait (Galaxias maculatus) spawning grounds. G. maxima does not provide the right kind of micro-habitat required for whitebait spawning as the weed clogs waterways and has displaced tall fescue grass from riparian zones which would have been suitable spawning grounds.

Social Impact

Top of page

G. maxima is unlikely to have any serious affect on cultural heritage sites, but dense infestations may have a negative visual effect, ruining the aesthetic appeal of waterbodies.  Clarke et al. (2004) recorded that G. maxima may convert sections of fast-flowing streams into anaerobic, swampy environments. Such a dramatic change could affect recreational fishing as downstream fish habitat would be significantly affected by reduced water flow. Dense infestations may also diminish recreational opportunities as swimming, boating, fishing and other recreational activities may be restricted.

Risk and Impact Factors

Top of page Invasiveness
  • Invasive in its native range
  • Proved invasive outside its native range
  • Has a broad native range
  • Abundant in its native range
  • Long lived
  • Fast growing
  • Has high reproductive potential
  • Gregarious
  • Has propagules that can remain viable for more than one year
  • Reproduces asexually
Impact outcomes
  • Damaged ecosystem services
  • Ecosystem change/ habitat alteration
  • Modification of hydrology
  • Modification of natural benthic communities
  • Modification of nutrient regime
  • Monoculture formation
  • Negatively impacts agriculture
  • Negatively impacts animal health
  • Negatively impacts livelihoods
  • Reduced amenity values
  • Reduced native biodiversity
  • Threat to/ loss of native species
Impact mechanisms
  • Competition - monopolizing resources
  • Competition - smothering
  • Poisoning
  • Rapid growth
Likelihood of entry/control
  • Highly likely to be transported internationally deliberately
  • Difficult/costly to control

Uses

Top of page

Economic Value

In its natural range G. maxima can be readily consumed by cattle and is considered a nutritious fodder. G. maxima was commercially planted in its invaded range as a ponded pasture grass in and around farm swamps, dams and streams (Walsh, 1994).

Environmental Services

G. maxima is used to treat sewage water in Europe and New Zealand because it has a high capacity to uptake nutrients (Ozimek and Klekot, 1979; Sundblad and Robertson, 1988; Sunblad and Wittgren, 1989; Tanner, 1996). As it slows water movement it can be useful for reducing erosion of riverbanks (Gippsland and Northern Co-operative Co. Ltd., 1940; DPIWE, 2009).

Uses List

Top of page

Animal feed, fodder, forage

  • Fodder/animal feed

Ornamental

  • Seed trade

Similarities to Other Species/Conditions

Top of page

G. maxima is similar to Glyceria grandis, the American mannagrass, which is native to <_st13a_place _w3a_st="on">North America (IPANE, 2009). Dore and McNeil (1980) provide one of the few keys among North American manuals which distinguishes G. maxima from G. grandis. They separate G. maxima by the length of the lower glume (2-3 mm versus 1.2 -1.5 mm in G. grandis). It is distinguished from other European species by its firmly erect stems. Others are generally decumbent and/or submerged.

Prevention and Control

Top of page

Prevention

Appropriate legislation is required to prevent the spread of G. maxima into susceptible areas. However, unless G. maxima is listed appropriately (e.g. as a declared or restricted weed), it will not fall under legislative restrictions.

Forecasts of the potential distribution of G. maxima can help to identify areas susceptible to invasion. The forecasts can inform decision-making for prevention schemes and assist targeted field sampling for the development of monitoring programmes and allow prioritization of control methods. Forecasts of the potential distribution of G. maxima in Australia have been undertaken by Loo et al. (2009a) and Weiss and Iaconis (2000). In New Zealand, the government is establishing a border control programme for aquatic plants that have the potential to become ecological weeds in New Zealand. The programme includes weed risk models that incorporate forecasts of the potential distribution, and an Aquatic Plant Weed Risk Assessment Model (Champion and Clayton, 2000, 2001).

Loo et al. (2009) found that the presence of G. maxima was negatively correlated with the amount of woody riparian vegetation. Riparian shading limits the spread and abundance of aquatic macrophytes, and G. maxima is only tolerant of light shade (Lambert, 1947; Bunn et al., 1998). Hence, the policy and management actions to maintain or restore riparian zones are likely to assist in the prevention of the spread of G. maxima.

The prevention of aquatic weed spread is the responsibility of all individuals and groups. Examples of prevention methods:
· Drainage contractors - ensure any weed is removed from machinery before moving to other waterbodies and waterways 
· Fishermen and eelers - remove all fragments of weed from nets before leaving the area
· Boat operators - check boats, motors and trailers for tag-along weeds immediately on removal of equipment from the water
· Aquarium owners - don’t dispose of aquarium contents into or near a waterway
· Duck shooters - check dogs, boots and boats for weed before leaving the area
· Landowners - don’t allow drainage equipment, nets or boats into waterbodies on their property unless they are free of weeds (DOC, 2009).

Public Awareness

Increased community awareness of the issue will be essential for successful control of aquatic weed species. The “Clean, Check, Dry principles” should be promoted to all users of waterbodies (DOC, 2009).

Early detection and confinement of new satellite populations are crucial, and will be possible only through targeted monitoring, and these monitoring systems need to be implemented using designs that recognize multiscale relationships (Mack, 2000; Olckers, 2004). A community-based weed detection network could play an important role in the early detection of new populations.

Control

Physical/mechanical control

Mechanical removal, such as excavation or hand pulling, can be used to control G. maxima, but may be ineffective if the entire rhizome system is not removed (Parsons and Cuthbertson, 1992). Manual removal works best with small plants. Excavation is not a preferred management approach for waterways because using heavy equipment may damage the structure of the waterway (Weiss and Iaconis, 2000). Excavation is more suitable for use on farm dams and can be useful at reducing the size of large infestations, allowing easier follow up by manual removal of small plants and regrowth. Excavated material should be dumped well away from the area at a site where it can dry out and kill all plants.

Black plastic used to smother the grass was 100% effective in Massachusetts, USA. However, this method is not feasible over large areas (Rawinski, undated, in Martin, 2009). Cutting may reduce populations of reed sweet-grass by allowing sunlight to reach other, competitive plants. Multiple cuttings (more than three) may reduce the amount of carbohydrates stored in the rhizomes. Cutting during the autumn months when carbohydrates and nutrients are stored for the winter may affect spring regrowth (Sundblad and Robertson, 1988).

Chemical control

G. maxima can be almost controlled or in some instances completely eradicated using herbicides, such as glyphosate or dalapon, which are translocated through all parts of the plant. Trials in Tasmania, showed G. maxima was eradicated by glyphosate when applied in autumn, and was almost completely controlled by dalapon 5 and 10 kg/ha + paraquat (Tasmanian Department of Agriculture, 1976). In the UK, glyphosate applied in summer and autumn gave almost total control (Barrett, 1976). In Holland, the application of dalapon + Amitrol-T (aminotriazole + ammonium thiocyanate) and glyphosate in early autumn completely killed the foliage, although glyphosate was slower acting (Stryckers and van Himme, 1974).

When using herbicides on G. maxima, a complete coverage of all foliage is necessary. Care must be taken in choosing and applying herbicides near waterways as to not impact upon the resident organisms (DPIWE, 2009). The glyphosate-based Roundup bioactive™ is the recommended herbicide because it is safe for use in or near waterways (Caffrey, 1996). Glyphosate should be applied in late summer and autumn, when the plants are in full flower. Where practical, the water level should be lowered to maximise plant exposure before treatment (Paterson and Cuthbertson, 1992; DPIWE, 2009).

However, chemical controls can have disadvantages. The mass of decaying vegetation that remains after treatment reduces the holding capacity of the waterway and the anaerobic decomposition of the material may render the water foul and unfit for use. In such cases mechanical removal of the plant material will be required. The disturbed space created after treatment provides ideal conditions for invasion by other weeds or by a re-infestation of G. maxima.

Ecosystem Restoration

G. maxima is sensitive to shade and appears to be out-competed once there is adequate cover of overstorey vegetation. The restoration of native riparian vegetation may be an effective long-term means of controlling invasive aquatic macrophytes, such as G. maxima.

Aquatic weed management requires an integrated catchment approach that recognizes the role that anthropogenic environmental change (such as the removal of riparian vegetation and increased soil nutrient content) has played in the spread of aquatic weed species (Loo et al., 2009a).

Gaps in Knowledge/Research Needs

Top of page

Greater information on the ecological impacts of G. maxima in the invaded range is required.

There is limited information on the impacts of G. maxima on waterfowl from its native range and none from the invaded range. There is only one study on the impacts on macroinvertebrates (from Australia) (Clarke et al., 2004) and only one study on the impact on fish (from New Zealand) (Taylor and Kelly, 2001).

References

Top of page

Allan HH, 1940. A handbook of the naturalised flora of New Zealand. Wellington, New Zealand: E. V. Paul, government printer.

Anderson JE; Reznicek AA, 1994. Glyceria maxima (Poaceae) in New England. Rhodora, 96(885):97-101.

AQIS, 2009. ICON - import conditions database. Australian Quarantine and Inspection Service. unpaginated. http://www.aqis.gov.au/icon32/asp/ex_QueryResults.asp?Commodity=glyceria&Area=All+Countries&EndUse=All+End+Uses&QueryType=Search

Barrett PFR, 1976. The effect of dalapon and glyphosate on Glyceria maxima. In: Proceedings 1976 British Crop Protection Conference, Vol. 1. London, UK: British Crop Protection Council., 79-82.

Barton NJ; McOrist S; McQueen DS; O'Connor PF, 1983. Poisoning of cattle by Glyceria maxima. Australian Veterinary Journal, 60(7):220-221.

Brouillet L; Coursol F; Favreau M, 2006. VASCAN. The database of Canadian vascular plants. VASCAN. The database of Canadian vascular plants. unpaginated.

Brown AG, 1929. How to plant Poa aquatica. Adelaide Chronicles, 20 June. unpaginated.

Bunn SE; Davies PM; Kellaway DM; Prosser IP, 1998. Influence of invasive macrophytes on channel morphology and hydrology in an open tropical lowland stream, and potential control by riparian shading. Freshwater Biology, 39(1):171-178.

Burgess ND; Evans CE; Thomas GJ, 1990. Vegetation change on the Ouse Washes Wetland, England, 1972-1988 and effects on their conservation importance. Biological Conservation, 53:163-181.

Buttery BR; Lambert JM, 1965. Competition between Glyceria maxima and Phragmites communis in the region of Surlingham Broad. 1. The competition mechanism. Journal of Ecology, 53:163-181.

Caffrey JM, 1996. Glyphosate in fisheries management. Hydrobiologia, 340(1/3):259-263.

Champion PD; Clayton JS, 2000. Science for Conservation, No. 141. Wellington, New Zealand: Department of Conservation, 48 pp.

Champion PD; Clayton JS, 2001. Border control for potential aquatic weeds. Stage 2. Weed risk assessment. Science for Conservation, 185:30 pp.

Clarke A; Lake PS; O'Dowd DJ, 2004. Ecological impacts on aquatic macroinvertebrates following upland stream invasion by a ponded pasture grass (Glyceria maxima) in southern Australia. Marine and Freshwater Research, 55(7):709-713.

CPBA, 2009. Australia's virtual herbarium. Australia's virtual herbarium. Canberra, Australia: Centre for Plant Biodiversity Research, Australian Government, unpaginated. http://www.anbg.gov.au/avh/cgi-bin/avhxml.cgi

Davis PH, 1965-1988. Flora of Turkey and the east Aegean islands. Flora of Turkey and the east Aegean islands. unpaginated.

DOC, 2009. Help stop the spread of freshwater weeds. Help stop the spread of freshwater weeds., New Zealand: Department of Conservation, unpaginated. http://www.doc.govt.nz/conservation/threats-and-impacts/weeds/freshwater-weeds/

Dore WG, 1947. Glyceria maxima in Canada. Canadian Field Naturalist, 61:174.

Dore WG; McNeil J, 1980. Grasses of Ontario. Monograph 26. Ottawa, Canada: Biosystematics Research Institute, Research Branch, Agriculture Canada.

DPIWE, 2009. Weeds, pests and diseases: Glyceria/reed sweet grass (Glyceria maxima - poa aquatica [Hartm.] Holmb.). Weeds, pests and diseases: Glyceria/reed sweet grass (Glyceria maxima - poa aquatica [Hartm.] Holmb.). Tasmania, Australia: Department of Primary Industries, Parks, Water and Environment, unpaginated. http://www.dpiw.tas.gov.au/inter.nsf/WebPages/RPIO-4ZV7D8?open

eBay, 2009. eBay. eBay. unpaginated. http://cgi.ebay.com/Glyceria-Maxima-Seeds_W0QQitemZ250434751392QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a4f130ba0&_trksid=p3286.m20.l1116

Flora Italiana, 2009. Flora Italiana. Flora Italiana. unpaginated. http://luirig.altervista.org/flora/glyceria.htm

Flora of China Editorial Committee, 2006. Flora of China. Flora of China, 22. 213-216. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=113749

Gippsland and Northern Co-operative CoLtd, 1940. G & N pedigree seeds catalogue. G & N pedigree seeds catalogue. Melbourne, Australia: The Company, unpaginated.

Haslam SE, 1978. River plants: the macrophytic vegetation of watercourses. Cambridge, UK: Cambridge University Press.

IPANE (Invasive Plant Atlas of New England), 2009. Glyceria maxima (reed mannagrass, reed sweetgrass). Glyceria maxima (reed mannagrass, reed sweetgrass). University of Connecticut, unpaginated. http://nbii-nin.ciesin.columbia.edu/ipane/icat/browse.do?specieId=54

ISSG, 2009. Global Invasive Species Database (GISD). Invasive Species Specialist Group of the IUCN Species Survival Commission. http://www.issg.org/database

LAMBERT JM, 1947. The Biological flora of the British Isles. Glyceria maxima (Hartm.) Holmb. L.C. (Ed. 11). No. 2190. Journal of Ecology, 34:310-44.

Larson D, 2003. Predicting the threats to ecosystem function and economy of alien vascular plants in freshwater environments. Literature review. Predicting the threats to ecosystem function and economy of alien vascular plants in freshwater environments. Literature review. Uppsala, Sweden: Department of Environmental Assessment, Swedish University of Agricultural Sciences.

Loo SE; MacNally R; O'Dowd DJ; Lake PS, 2009. Secondary invasions: implications of riparian restoration for in-stream invasion by an aquatic grass. Restoration Ecology, 17(3):378-385. http://www.blackwell-synergy.com/loi/rec

Loo SE; Nally RM; O'Dowd DJ; Thomson JR; Lake PS, 2009. Multiple scale analysis of factors influencing the distribution of an invasive aquatic grass. Biological Invasions, 11(8):1903-1912. http://www.springerlink.com/content/wn67q760w336876j/fulltext.html

Mack RN, 2000. Assessing the extent, status and dynamism of plant invasions: current and emerging approaches. In: Invasive species in a changing world [ed. by Mooney, H. A.\Hobbs, R. J.]. Washington, D.C., USA: Island Press, 141-168.

Martin T, 2009. Glyceria maxima. Global invasive species team, the nature conservancy. Glyceria maxima. Global invasive species team, the nature conservancy. unpaginated. http://wiki.bugwood.org/Glyceria_maxima

Melbourne Water, 2003. Weed fact sheet - reed sweet grass, Glyceria maxima. Weed fact sheet - reed sweet grass, Glyceria maxima. Melbourne, Australia: Melbourne Water, unpaginated.

Missouri Botanical Garden, 2010. Tropicos database. Tropicos database. St Louis, USA: Missouri Botanical Garden. http://www.tropicos.org

Olckers T, 2004. Targeting emergent weeds for biological control in South Africa: the benefits of halting the spread of alien plants at an early stage of their invasion. South African Journal of Science, 100:64-68.

Ozimek T; Klekot L, 1979. Glyceria maxima (Hartm.) Holmb. in ponds supplied with post-sewage water. Aquatic Botany, 7(3):231-239.

Parsons WT; Cuthbertson EG, 1992. Noxious Weeds of Australia. Melbourne, Australia: Inkata Press, 692 pp.

Peeters A, 2005. Grassland and pasture crops: Glyceria maxima/ (Hartm.) Holmberg. Grassland and pasture crops: Glyceria maxima/ (Hartm.) Holmberg. unpaginated.

Reed R, 1987. Wisconsin vascular plants. Wisconsin vascular plants. unpaginated.

Sanity GR; Jacob SWL, 1994. Water plants in Australia. Sydney, Australia: Sanity and Associates.

Seeds-by-size, 2009. Ornamental grass seeds 2009/10 list. Ornamental grass seeds 2009/10 list. unpaginated. http://www.seeds-by-size.com/orngrass98.html

Stace R; Meijden van der; Kort Ide, 2009. Interactive flora of NW Europe. Interactive flora of NW Europe. Cambridge, UK: Cambridge University Press, unpaginated. http://nlbif.eti.uva.nl/bis/flora.php

Stryckers J; Van Himme M, 1974. Control of Glyceria maxima - review of the results obtained for the cropping year 1972-74. Control of Glyceria maxima - review of the results obtained for the cropping year 1972-74., Belgium: Rijksuniversiteit, unpaginated.

Sundblad K; Robertson K, 1988. Harvesting reed sweetgrass (Glyceria maxima, Poaceae): effects on growth and rhizome storage of carbohydrates. Economic Botany, 42(4):495-502.

Sundblad K; Wittgren HB, 1989. Glyceria maxima for wastewater nutrient removal and forage production. Biological Wastes, 27(1):29-42.

Tanner CC, 1996. Plants for constructed wetland treatment systems - a comparison of the growth and nutrient uptake of eight emergent species. Ecological Engineering, 7:59-83.

Tasmanian Department of Agriculture, 1976. Annual report 1975-76. Tasmania: Tasmanian Department of Agriculture, unpaginated.

Taylor MJ; Kelly GR, 2001. Inanga spawning habitats in the Wellington. Wellington regional council. Inanga spawning habitats in the Wellington. Wellington regional council. unpaginated. [NIWA Client Report: CHC01/67.] http://gw.govt.nz/council- publications/pdfs/Environment%20Management_20021022_163731.pdf

USDA-ARS, 2009. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx

USDA-NRCS, 2009. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/

Walsh NG, 1994. Flora of Victoria. 2 [ed. by Walsh, N. G.\Entwistle, T. G.]. Melbourne and Sydney, Australia: Inkata Press, 356-627.

Weiss JER; Iaconis LJ, 2000. Glyceria maxima, reed sweet-grass: an assessment of weed potential for Melbourne water. Glyceria maxima, reed sweet-grass: an assessment of weed potential for Melbourne water. Melbourne, Australia: Keith Turnbull Research Institute, unpaginated.

Western Australian Herbarium, 2009. Florabase - the Western Australian flora. Florabase - the Western Australian flora. Western, Australia: Department of Environment and Conservation, unpaginated. http://florabase.calm.wa.gov.au/browse/map/437

Links to Websites

Top of page
WebsiteURLComment
Australia’s Virtual Herbarium.http://avh.ala.org.au/
Bugwood wiki Glyceria maximahttp://wiki.bugwood.org/Glyceria_maxima
GISD/IASPMR: Invasive Alien Species Pathway Management Resource and DAISIE European Invasive Alien Species Gatewayhttps://doi.org/10.5061/dryad.m93f6Data source for updated system data added to species habitat list.
Global register of Introduced and Invasive species (GRIIS)http://griis.org/Data source for updated system data added to species habitat list.
Interactive flora of NW Europehttp://nlbif.eti.uva.nl/bis/flora.php

Contributors

Top of page

10/09/09 Original text by:

Sarina Loo, Sustainable Water, Environment & Innovation Division, Dept. of Sustainability and Environment, Level 12, 8 Nicholson Street, East Melbourne VIC 3002, Australia

Distribution Maps

Top of page
You can pan and zoom the map
Save map