Quick Facts

Quick facts

• Common Cord-grass (Spartina anglica) is an extremely successful invasive plant into intertidal and saline to subsaline, near-coastal areas prone to inundation in southern Australia.
• Common Cord-grass invasions impact on both animal and plant biotas, particularly on wading birds and small molluscs and crustaceans.
• It reproduces by seed and by fragmentation and dispersal of rhizomes.
• It is derived from a sterile, hybrid species, S. × townsendii.
• Other members of the genus (particularly S. × townsendii) may occur and may have similarly detrimental effects on intertidal habitats.

What Does It Look Like?

What is it?

Common Cord-grass (Spartina anglica) is a deep-rooted perennial grass, which initially forms clumps but often spreads to form extensive swards. Leaves are smooth and hairless, and the blade is flat or folded and tapered to a fine, hard point. It reaches 45 cm long and 15 mm wide, with a collar of dense hairs ( a ligule) 2–3 mm long at the base. Flowering stems are erect and 30–130 cm tall, with 2–6 yellowish spikes, which are up to 25 cm long and terminate in a bristle 1–4 cm long. The flowers (spikelets) occur in two rows, which are closely pressed against the triangular flower stem (axis). Individual flowers have 2 unequal outer bracts (glumes), the longer 14–21 mm long and the shorter about 10–15 mm long. The larger of the 2 inner bracts (lemma) is approximately midway in length between the 2 glumes, and the shorter (palea) is about as long as the lower glume. The anthers are 8–13 mm long (Hubbard 1968; Walsh 1994).

For further information and assistance with identification of Common Cord-grass contact the herbarium in your state or territory.

Flower colour

Green

Growth form (weed type/habit)

Grass, Aquatic

Where it currently grows? Preferred habitat

Common Cord-grass is found in coastal saltmarshes, mangrove shrublands, mudflats and edges of tidal streams and channels (National Herbarium of Victoria 2007; Muyt 2001; Walsh 2007, pers. comm.).

Are there similar species?

Other species of Spartina are likely to be confused with Common Cord-grass, and in most, if not all cases, this is likely to be of little consequence, all species having similar consequences to intertidal communities. The major difference between Common Cord-grass (S. anglica) and S. × townsendii (the other species most likely to be encountered) is the presence of larger (longer than 8 mm), fertile anthers in Common Cord-grass. The anthers of S. × townsendii are up to 8 mm long, but do not contain fertile pollen, rendering the plant unable to produce viable seed (Walsh 1994).

In the vegetative stage, Common Cord-grass may be confused with the Native Common Reed, Phragmites australis [as Phragmites communis], but this is generally a larger plant (to 3 m high or more), with broader leaves that are carried on an erect hollow stem, not mostly tufted at the base as in Spartina. In flower, Native Common Reed is readily distinguished by the feathery flower head that contains very many seeds, each released with a tuft of fine hairs enabling it to become windborne (Walsh 2007, pers. comm.).

Because grasses in general are a difficult group to identify, where there is any doubt about the identity of a plant suspected of being a Spartina species, specialist help should be sought.

Why Is It A Weed?

What are its impacts?

Common Cord-grass was included in the list of 71 species that were nominated by state and territory governments for assessment as Weeds of National Significance (WONS). Following an assessment process, Common Cord-grass was not included as one of the 20 WONS. However, it remains a weed of potential national significance.

Native ecosystems: Common Cord-grass invasion has resulted in the alteration of coastal environments – transforming saltmarsh and mangrove communities and sandy beaches into 'Spartina meadows' (Muyt 2001; Walsh 2007, pers. comm.). The effects on biota in these habitats is largely unknown in Australia, but there is evidence that wader-bird use of areas previously free of Common Cord-grass declines significantly following invasion by the grass (Simpson 1996).

Based largely on non-Australian studies, one effect is believed to be as a direct consequence of change of structure of the community, from a low-open herbland/shrubland, to relatively tall, dense grassland. The availability of food species such as small crustaceans and molluscs is almost certainly affected too, further rendering habitats unsuitable for fauna that depend on these (Lee & Choy 2004).

Human impacts: Social impacts include rendering boating and boat launching facilities inoperable due to accretion of sediments by Common Cord-grass plants (Walsh 2007, pers. comm.).

Agriculture: Common Cord-grass infestations can also affect oyster farming in the intertidal areas and change hydrodynamics (Kriwoken & Hedge 2000).

How does it spread?

Dispersal of Common Cord-grass occurs through dissemination of seed, which is able to survive immersion in seawater for considerable periods, and through fragmentation and dispersal to new sites by water movement (Walsh 2007, pers. comm.). In the past, its spread by humans has been from sown seed and transport of 'runners' (sections of rhizome). The ripe seed includes an abnormally large, well-developed embryo which is capable of photosynthesis at the time of dispersal (Walsh 2007, pers. comm.).

What is its history in Australia?

Common Cord-grass was introduced to several sites along the north and east coast of Tasmania in 1930 and by 1947 had 'taken' on the Tamar River (Wells 1996). Common Cord-grass was introduced into Victoria, at Lake Connewarre on the lower Barwon River estuary in 1930-1931, and along the South Gippsland coast in 1932, but it is unclear whether this was S. × townsendii or S. anglica (Walsh 2007, pers.comm.). At Lake Connewarre more than 3,000 plants were introduced with the intention to reclaim 'much of the shallow lake bed, which it is thought will eventually become good grazing land' (Boekel 1996). The introduced plants survived but did not thrive.

It was not reported again in the Barwon River until 1994, when both S. × townsendii and S. anglica were confirmed (the latter possibly by in situ genetic modification from the 'parent' species S. × townsendii) (Boekel 1996). Subsequent plantings in South Gippsland in 1962 were more likely to have been of S. anglica, as, after this attempt, there was successful establishment and rapid expansion of plants, particularly in the Andersons Inlet area. There were also attempts to establish Common Cord-grass (believed to have been S. × townsendii) in Western Australia and South Australia, but these appear to have been unsuccessful (Keighery 1966; Fotheringham et al. 1996)

How To Manage It?

Best practice management

A number of control techniques have been trialled for Common Cord-grass in Australia, most actively in Tasmania, but also in Victoria.

Non-chemical control: Hand-weeding is only suitable for small infestations, and carries the risk of fragmenting of rhizomes that may then establish elsewhere (Rice Grass Advisory Group 2002).

Smothering the infestation with, for example, opaque plastic sheeting which is left in place for several months can prove very effective (up to 100% kill of Spartina), but is applicable only on small infestations. It is also not selective and is likely to destroy animal, as well as plant, components of the smothered area (Rice Grass Advisory Group 2002).

Grazing reduces biomass, but does not generally destroy the plants (Rice Grass Advisory Group 2002).

Chemical control: Treatment with certain herbicides, which are selective to grasses, and appear to be of low toxicity to intertidal invertebrates, can provide good kill (Rice Grass Advisory Group 2002). Also see Shaw & Gosling (1996) for a summary of trials undertaken in New Zealand.

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au .

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Common Cord-grass flowers from December to March (Walsh 1994) and seed matures during this period to as late as June (National Herbarium of Victoria 2007). Seedlings may establish soon after dispersal, but seeds probably remain viable for considerable periods and later germinations are likely (Walsh 2007, pers. comm.).

Where Is It Found?

Which states and territories is it found?

TAS, VIC

What areas within states and territories is it found?

In Victoria, Common Cord-grass occurs in the lower estuary of the Barwon River, between Tooradin and San Remo in Western Port, in the Andersons Inlet–Venus Bay area, and in several areas in Corner Inlet (e.g., Foster Beach, Toora, Port Albert) (National Herbarium of Victoria 2007). There is a specimen from 1947 at the National Herbarium of Victoria of Common Cord-grass (species uncertain) from Sunday Island in Corner Inlet, but there have been no recent records of the grass from that area.

In Tasmania Common Cord-grass has been recorded from the north-west at Robbins Passage, Smithton and Stanley; across the northern coast at Port Sorell, the estuary of the Tamar River and Bridport; along the east coast at St Helens, Little Swanport and along the Derwent River near Hobart (Wells 1996). Control measures in the latter four localities have resulted in near-complete eradication (RPDC 2003).

Temperatures at latitudes north of 35°S may be too high for Common Cord-grass to set seed (Ranwell 1975). This may partly explain the failure for the Western Australian and South Australian plantings to establish.

Where does it originate?

Common Cord-grass was derived from Spartina × townsendii, a hybrid between the largely western European species S. maritima and an American species S. alterniflora (Hubbard 1968). The hybrid arose in Hampshire, the Isle of Wight, and on the northern coast of France as a result of the introduction of S. alterniflora into areas where S. maritima was naturally occurring. The hybrid, later described as S. × townsendii, was first noticed in 1870. It was male-sterile (i.e., its anthers contained no fertile pollen), but readily spread by vegetative growth.

In 1892, it was observed that the sterile hybrid had 'overcome' its sterility through a duplication of chromosomes (a phenomenon known as 'amphipolyploidy'), and was now a sexually reproducing species (Hubbard 1968) and was later named Spartina anglica. Its ability to 'reclaim' mudflats through the accumulation of silt and other debris was soon acknowledged and it became used widely on shallow shores to increase the amount of useable ground (e.g., for pasture) (Hubbard 1968).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

VIC, WA

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Spartina anglica

Other scientific names (synonyms)?

Spartina x townsendii H.Groves & J.Groves (misapplied by Townrow, J.E.S. 1969, A species list of and keys to the grasses of Tasmania. Papers and Proceedings of the Royal Society of Tasmania. 103: 73.)

Does it have other known common name(s)?

Rice Grass, Cord Grass, Spartina