Quick Facts

Quick facts

• Noogoora Burr (Xanthium strumarium) is a major weed of disturbed soil, flood plains and the agricultural land of Australia, particularly in Queensland, the Northern Territory and New South Wales.
• It is an important cause of vegetable contamination of wool.
• It is easily recognisable by its large adult leaves and spiny burrs.
• It is dispersed readily, particularly along water courses and across floodplains.
• Plants are not eaten by animals and are poisonous to stock.

What Does It Look Like?

What is it?

Noogoora Burr (Xanthium strumarium) is a multi-stemmed or single stemmed herb growing up to 2 m high. Its stems are hairy but without spines. The leaves are broad-ovate to triangular, 50–150 mm long, 50–150 mm wide, 3- or 5-lobed, with a lobed base and toothed margins. The upper leaf surface is darker green than the under surface and prominently 3-veined with purplish veins. The leaf stalk (petiole) is 20–120 mm long (modified from Cross et al., unpublished).

The flowers are unisexual with separate male and female flowers on the same plant. The cream or creamy green male flowers are clustered at the end of the branches, or in the upper leaf axils while the yellowish green to brown female flower heads occur in the leaf junctions.

The burrs (fruit) are ellipsoid, 15–25 mm long, with glandular & non-glandular hairs, covered with numerous hooked spines and with 2 longer stout and straight spines (or 'beaks'). Two seeds formed in each burr, one larger than the other (modified from Cross et al., unpublished).

Noogoora Burr is a complex and variable species, and some jurisdictions recognise segregate entities in addition to Xanthium strumarium (e.g. Xanthium californicum and Xanthium occidentale in South Australia, as well as Xanthium cavanillensii, Xanthium italicum, Xanthium occidentale and Xanthium orientale in New South Wales). The Flora of Australia recognition of this group (unpublished) will treat these different forms of Noogoora Burr under one name, Xanthium strumarium.

For further information and assistance with identification of Noogoora Burr contact the herbarium in your state or territory.

Flower colour

Yellow, Green

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

Noogoora Burr is widespread in low-lying areas subject to inundation, rivers and creeks and flats after late spring or summer flooding in all mainland states (Cross et al., unpublished).

Are there similar species?

Noogoora Burr is a complex and variable species, and some jurisdictions recognise segregate entities in addition to Xanthium strumarium (e.g. Xanthium californicum and Xanthium occidentale in South Australia, as well as Xanthium cavanillensii, Xanthium italicum, Xanthium occidentale and Xanthium orientale in New South Wales). The Flora of Australia recognition of this group (unpublished) will treat these different forms of Noogoora Burr under one name, Xanthium strumarium.

Noogoora Burr (Xanthium strumarium) may be confused with Bathurst Burr (Xanthium spinosum), another common weed throughout Australia. Both species have similar looking burrs covered with hooked spines. They can be easily separated as Bathurst Burr has three long sharp spines on the stem at the base of each leaf, while Noogoora Burr is spineless. Bathurst burr also has narrow adult leaves 8-22 mm wide and burrs with small or no beaks, while Noogoora Burr has broad adult leaves, usually 50-150 mm wide, and burrs with two distinct beaks (Navie 2004).

Why Is It A Weed?

What are its impacts?

Noogoora Burr 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, Noogoora Burr was not included as one of the 20 WONS. However, it remains a weed of potential national significance.

Agriculture: The burrs of Noogoora Burr are an important cause of vegetable contamination of wool in wool growing areas, making fleeces harder to work with and reducing their value. Seedlings are poisonous to livestock, particularly horses and pigs. Some people may develop dermatitis after contact with the plant and the pollen may cause hay fever. An extensive root system and rapid growth rate makes Noogoora Burr a serious competitor for pastures and cropping (Parsons & Cuthbertson 1992).

Native ecosystems: Noogoora Burr has a strong preference for drainage lines and alluvial flats and also occurs on heavy clays of the 'black soil plains'. It forms large dense thickets which can virtually exclude other understorey plants and thus is a threat to the biodiversity of wetland plants (Duguid et al. 2002).

How does it spread?

The burrs of Noogoora Burr are covered in hooked spines and transport readily by attaching to livestock, clothing and other fibrous material. They are also spread in mud and soil, road gravel and road making equipment. Air cavities around the seeds assist the burrs to float on water and hence much of the spread in Australia has been along waterways and across flood plains (Parsons & Cuthbertson 1992).

What is its history in Australia?

Noogoora Burr is thought to have been first introduced to Australia with cotton seed imported from either the Mississippi Delta region of the United States or from India and was first recorded at Noogoora Station on the Brisbane River, near Ipswich, Queensland in the 1860s. By the 1890s it had reached the north coast of New South Wales and quickly spread throughout the remaining grazing land in western and central Queensland, and central New South Wales, also becoming established in floodplains of the coastal rivers north of Sydney. In the 1950s to the late 1970s, a series of floods caused extensive spread in western New South Wales. It now extends throughout much of New South Wales and Queensland, and has managed to spread to the other mainland states (Parsons & Cuthbertson 1992).

In the 1920s or 1930s, the Californian form of Noogoora Burr is believed to have been introduced into the grape growing areas of northern Victoria and South Australia through the importation of grape root stock from California (Parsons & Cuthbertson 1992).

How To Manage It?

Best practice management

Non-chemical control: Physical control: Hand hoeing or chipping is only economical for control of Noogoora Burr in small areas or sparsely populated situations. It is very labour intensive (NSW Agriculture 2004).

Grazing of Noogoora Burr plants is an option, using sheep before flowering and after the cotyledon leaves have dried. A number of researchers and graziers have maintained that adult plants are not easily eaten by livestock, because of the roughness of the leaves and stems. Care needs to be taken with grazing to ensure there are no seedling plants, which could kill animals (NSW Agriculture 2004).

Chemical control: Both Noogoora and Californian burrs are susceptible to herbicides suited to a range of situations and regulations. Chemicals are most effective if the plants are young and actively growing. Plants under severe moisture or weather stress are difficult to kill (NSW Agriculture 2004). Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au .

Biological control: A rust fungus, Puccinia xanthii, was first found in Australia near Brisbane in 1975 and then at Narrabri in 1978. Attack by P. xanthii has been shown to shorten the plant life cycle and reduce plant growth rate and productivity. Burr production was reduced by up to 59% but percentage seed germination remained unchanged.

In parts of New South Wales and Queensland, the rust can be effective in controlling both species, but timing and rate of spread depends on warm and humid conditions (NSW Agriculture 2004)

Noogoora Burr has been recognised as a target for biological control through a cross-jurisdictional government process. This allows activities to be undertaken to develop effective biological controls. Since 1932 there have been four species introduced for controlling Noogoora Burr in Queensland, including Epiblema strenuana, a stem galling moth which was introduced into Australia in 1982 for the control of parthenium weed in Queensland and was found to be also affecting Noogoora Burr. In 1984 specific releases of the moth were made on Noogoora Burr in Queensland, where it has reduced the vigour of the plant.

Unfortunately, these insects have had little or no effect in controlling Noogoora Burr within most of New South Wales because of the different variable climatic conditions of south-eastern Australia where Noogoora Burr is a problem (NSW Agriculture 2004).

Does it have a biological control agent?

YES

When does it grow? (lifecycle/growth calendar)

Open Noogoora Burr plants produce 500 to 5 400 burrs per plant. The number of fruits produced is dependent upon the amount of vegetative growth at the time of floral initiation. On crowded plants, production is reduced to 71 to 586 burrs per plant (Weaver & Lechowicz 1983).

Germination of Noogoora Burr seeds has been extensively researched (Crocker 1906; Davis 1930, Katoh & Esashi 1975, Zimmerman & Weis 1983). More than 80% of Noogoora Burr seeds are viable in most populations (Weaver & Lechowicz 1983). Light is not required for germination, but seedlings seldom emerge from seeds lying on the surface or buried more than 15 cm in the soil (Kaul 1965a; Stoller & Wax 1973).

Seeds of Noogoora Burr have a high moisture requirement for germination (Kaul 1968). Noogoora Burr seed viability decreases over time, and seeds do not survive more than a few years (Wapshere 1974b).

Seedlings are unusually large with foliar-type cotyledons that, through early photosynthetic function, enable the young seedling to become quickly established (Polunin 1966). Seedlings may be identified in the cotyledon stage by the presence (below ground) of the persistent bur, which usually remains attached to the seedling (Kingsbury 1964).

Noogoora Burr plants produce seeds of two types. Each burr contains two seeds, with the smaller one often pushed upwards toward the beaked end of the fruit. The lower seed has a shorter dormant period and germinates first. Having at least two batches of seeds present in each generation is thought to assure germination in the event the immediate environment happens to be unsuitable (Redosevich & Holt 1984).

Growth is rapid in warm weather and burrs form from February to May. Plants die in late autumn but remain standing, bearing mature burrs for many months. Plants from seeds germinating late in summer produce burrs at a very early age when the plants are only a few centimetres high (Parsons & Cuthbertson 1992).

The species does not reproduce vegetatively (Weaver & Lechowicz 1983).

Where Is It Found?

Which states and territories is it found?

ACT, NSW, NT, QLD, SA, VIC, WA

What areas within states and territories is it found?

Noogoora Burr is widespread throughout most parts of New South Wales and Queensland, extending across into the Northern Territory, particularly around the Katherine, Daly Waters and Darwin regions and also the river systems flowing into the Gulf of Carpentaria. A few collections have been recorded from around the Alice Springs region. It also has a scattered distribution through northern Victoria and eastern South Australia, particularly around the Murray River and some tributaries. A few infestations have been recorded from the Kimberley region and the Perth region of Western Australia. One infestation was recorded in Tasmania but has since been eradicated (Parsons & Cuthbertson 1992; AVH 2007).

Where does it originate?

Noogoora Burr is a native of North America (Parsons & Cuthbertson 1992).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

NSW, NT, SA, TAS, 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

Xanthium strumarium

Other scientific names (synonyms)?

Xanthium strumarium has had numerous names applies with some states using that name, while others use one of the names below. There may be one or more similar looking species, but until the taxonomy is resolved the name Xanthium strumarium refers to that species and all names below:

• Xanthium californicum Greene
• Xanthium canadense Mill.
• Xanthium cavanillesii Schouw
• Xanthium chinense Mill.
• Xanthium commune Britton
• Xanthium italicum Moretti
• Xanthium occidentale Bertol.
• Xanthium orientale L.
• Xanthium pungens Wallr.
• Xanthium strumarium subsp. italicum (Moretti) D.Love

Does it have other known common name(s)?

Cockleburr, Clotbur, Large Cockleburr, Rough Cockleburr, Californian Burr, European Cocklebur