Quick Facts

Quick facts

  • Mesquite (Prosopis spp.), which includes several hybrids, is one of four species of prickle bushes that have infestations scattered throughout semi-arid Australia.
  • Mesquite can either be a multi-stemmed shrub or a single stemmed tree with a spreading canopy.
  • Mesquite are highly adapted for growing in arid conditions making them extremely successful weeds in Australia.
  • It is a nuisance in rangelands where it forms dense impenetrable stands, particularly around waterways.
  • Animals eat the seed pods and spread the seeds. Historical control efforts by mechanical and chemical means have been expensive and ultimately ineffective.
  • Control requires an integrated management approach, including mechanical, chemical and biological techniques and the use of fire and grazing strategies.

What Does It Look Like?

What is it?

The various Mesquite species (Prosopis spp.) come in a range of shapes and sizes. They can be found as multi-stemmed shrubby bushes or single stemmed trees with a spreading canopy often with an irregular outline with some branches protruding out of the canopy, growing from 3 to 15 m tall. The bark is smooth and dark red-green in young stems, and rough and grey in older stems. Branches have a characteristic zig-zag structure, and the overall impression is of a rather untidy plant, with single branches extending outside the main canopy. Mesquite leaves occur at each point where the branch changes direction (the zig-zag) and are compound (twice-divided), with 1-4 pairs of primary leaflets each with 7-21 pairs of small opposite secondary leaflets. There are often one or two thorns at the base of the leaves.

The greenish cream-yellow flowers form a cylindrical flowerhead 50-80 mm in length.

Fruit are formed as pods which are 5-20 cm long, compressed, straight to curved, smooth or with slight restrictions between the seeds. Ripe pods are yellow, purple, or yellow with purple streaks and patches. The flat seeds are oval or elliptical 2.5-7 mm long by 2-3 mm wide, each enclosed in a flattened fibrous case, and surrounded by sweet pulp (CRC 2003; DAFWA).

Identification of Mesquite species is complicated because there is often variation in growth form, even within the same species, and hybrids between the main species are common. For further information and assistance with identification of Mesquite contact the herbarium in your state or territory.

Flower colour

Green, Yellow

Growth form (weed type/habit)

Tree, Shrub

Where it currently grows? Preferred habitat

In general, Mesquite species are well adapted to hot climates and a wide range of soil types and annual rainfall (150-1200 mm). They can tolerate droughts and waterlogging, low nutrient soil and highly saline or alkaline soil. In northern Australia, Mesquite prefers semi-arid to arid rangelands that are prone to flooding and soils that have good moisture retention (CRC 2003; DAFWA).

Are there similar species?

Mesquite is similar to the other prickly weeds Mimosa Bush (Vachellia farnesiana) [as Acacia farnesiana], Parkinsonia (Parkinsonia aculeata) and Prickly Acacia (Vachellia nilotica) [as Acacia nilotica]. Mimosa Bush has a smaller pod and flowers in globular balls. Parkinsonia leaves are narrow and once-compound, and the large flowers have distinct petals. Prickly Acacia has globular flowerheads and a large pod with distinct constrictions between the seeds (CRC 2003).

Why Is It A Weed?

What are its impacts?

Mesquite is a Weed of National Significance. It is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts. Environmental impacts include land erosion resulting from the loss of grassland habitat that supports native plants and animals; and the provision of safe refuges for feral animals such as pigs and cats (CRC 2003). Mesquite can also increase land degradation and loss of soil moisture due to its extensive and deep root system (Osmond 2003).

Agricultural: Mesquite's economic impacts stem from its habit of forming dense, impenetrable thickets which, combined with its large thorns, prevent stock accessing watering holes and make mustering difficult. Mesquite also reduces the productivity of pastoral country by taking over grasslands and using valuable water resources. The sharp thorns damage animal hooves, puncture vehicle tyres, and inflict injury to people (Osmond 2003). Livestock which consume excessive amounts of seed pods can be poisoned (CRC 2003).

Environment: Mesquite can cause increased land degradation and loss of soil moisture. It reduces biodiversity by outcompeting native plants. It also acts as a refuge for feral animals (Osmond 2003).

Human: In 2003 it was estimated that $20000 per year was spent on the medical treatment for injuries caused by the the thorns of Mesquite (E Miller pers. comm. in Osmond 2003).

How does it spread?

Mesquite mainly reproduces via seeds, producing one main crop annually. Each seed pod generally carries between 5 and 20 seeds, with potentially hundreds of thousands of seeds produced per mature plant. Humans have assisted the spread of Mesquite throughout Australia and the rest of the world (CRC 2003).

Animals consume the nutritious seed pods and excrete viable seed in their droppings, helping to spread Mesquite over shorter distances. Cattle are mainly responsible, although horses, pigs, goats, sheep, emus and kangaroos are also known to consume the seed pods. As long as the seeds themselves are not damaged by chewing, digestion actually helps germination, particularly as the expelled seeds are deposited in moist, nutrient-rich dung. Apart from deliberate plantings, animals – mainly cattle – are most responsible for spreading Mesquite. Seed pods can also be spread by flooding (CRC 2003).

What is its history in Australia?

Mesquite was originally planted as an ornamental, shade or fodder tree around stations in the Northern Territory and Queensland at the start of the 19th century, and in Western Australia and New South Wales a little later, but appeared to be little threat at first. It was also planted around mining sites around Cloncurry in Queensland and Broken Hill in New South Wales to reduce dust and erosion. It has subsequently escaped in every mainland state after favourable conditions in the mid-1900s provided it with the opportunity to spread. Because Mesquite has some properties that are considered useful to humans, including uses as building timber, fuel and livestock food, it has been introduced and naturalised around the world (CRC 2003; Osmond 2003).

Mesquite has been introduced to Hawaii, Jamaica, the Middle East, throughout Asia including the Indian subcontinent, and Africa including Nigeria, Sudan, Senegal and southern Africa. It is also one of the most serious weeds of the southwestern United States where nearly thirty Prosopis species are federally listed noxious weeds (CRC 2003; Kirkbride et al. 2006).

How To Manage It?

Best practice management

Control is possible using chemical, mechanical and biological methods, and a combination (integrated management). Current research is investigating integration of traditional management practices (chemical and mechanical control) with fire, grazing management and biological control, which are more time- and cost-effective mechanisms. An integrated management strategy for Mesquite will vary with the infestation's characteristics, including its size, age, density and habitat. In general, multi-stemmed mesquites are harder to control than single-stemmed trees (CRC 2003).

Chemical control: The basal bark and cut-stump techniques are effective on mature trees. Seedlings can be controlled by spraying foliar herbicide over the entire plant. This is particularly effective for dealing with actively growing, dense stands of Mesquite up to 1.5 m tall (CRC 2003). Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au .

Non-chemical control: Mechanical control techniques range from blade ploughing to grubbing and chaining. Mechanical control has varying levels of effectiveness depending on the size and species of the plant, but will kill Mesquite if the roots can be removed to a depth of 300 mm.

Fire can give good control of Mesquite, particularly Prosopis pallida. If necessary, mechanical control such as chaining can be used before burning to provide enough fuel to generate the heat required to kill Mesquite. Fire is relatively inexpensive and, even when it does not kill the entire plant, can reduce seed production by removing vegetation and killing seed lying on the ground surface. However, most of the other species of Mesquite are more resistant to fire, and resprout from the rootstock if the crown is removed by fire (CRC 2003).

Biological control: Mesquite has also 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.

Research for the biocontrol of mesquite (also called algaroba) (Prosopis L. spp. (Fabaceae)) in Australia commenced in early 1990s beginning with testing of two seed-feeding bruchids, from a biocontrol program initiated in South Africa (Harvey et al 2023).  Since this time, four species of insects have been released in Australia and include: the two seed-feeding bruchids (Algarobius bottimeri Kingsolver, Algarobius prosopis (Le Conte)) from North America, and a leaf-feeding psyllid (Prosopidopsylla flava Burckhardt) and leaf-tying moth (Evippe sp.) from Argentina (Harvey et al 2023).  Of these, only the seed feeding bruchid (A. prosopis) and the leaf-tying moth have established.  The leaf-tying moth is highly effective in suppressing the seed production and growth rate of mesquite, particularly in the Pilbara region of Western Australia.  Its presence in NSW however is rare and its impact is somewhat limiting in the Northern Territory and Queensland (Harvey et al 2023).  The seed feeding bruchid (A. prosopis) while widely established, exerts only limited population level regulation (van Klinken 2012; Winston et al. 2022).

For further information see the Mesquite Best Practice Manual (Osmond 2003) (available at https://www.weeds.org.au/WoNS/Mesquite/).

Does it have a biological control agent?

YES. Four biocontrol agents released: the seed-feeding bruchids (Algarobius bottimeri, Algarobius prosopis), a leaf-feeding psyllid (Prosopidopsylla flava) and leaf-tying moth (Evippe sp.) (Harvey,  et al 2023).


When does it grow? (lifecycle/growth calendar)

Mesquite has a long life cycle. In its native range plants live at least 30 years, but one specimen in the Brisbane Botanical Gardens is over 115 years old.

Because Mesquite is found over such a large area, and consists of several species and hybrids, there is much variation in its growth calendar. Its seeds can germinate year round as long as the soil is moist. The young seedlings are generally slow growing as resources are invested into establishing the root system. This can be extensive in mature trees, in some cases exceeding a depth of 50 m (CRC 2003). However, while plants generally flower and fruit for the first time between two and five years old, some have been observed to produce pods within their first year (Osmond 2003). Where winters are cold, Mesquite may shed its leaves in late autumn or early winter and undergo a dormant period until early spring (CRC 2003).

Flowering in Mesquite occurs mainly in spring and early summer. The seed pods take two to three months to mature and generally drop in late summer. The seeds are dormant when dropped – the hard outer casing must be damaged to allow moisture into the seed before germination can occur. Animal consumption, fire or wet conditions are all ways of breaking the seed casing. If the seed casing is not broken, seeds lying in soil can remain viable for very long periods (CRC 2003).

Where Is It Found?

Which states and territories is it found?


What areas within states and territories is it found?

There are four naturalised species of Mesquite in Australia, and a range of hybrids. Collectively, they are suited to the climate of much of inland Australia. The worst infestations are on pastoral land in the Pilbara in Western Australia, the Barkly Tablelands in the Northern Territory, and in north-western, central and south-western Queensland (CRC 2003).

Different species have different distributions, which reflect their initial plantings but also variation in their preferred climate and surroundings. For example, Prosopis pallida is widely distributed across the north of Australia from the east coast of Queensland through the Northern Territory to the west coast of Western Australia. However, it is not found in any of the southern states, whereas Prosopis velutina and the hybrid P. velutina x P. glandulosa var. torreyana can tolerate the cooler climate of southeastern Australia (CRC 2003).

Where does it originate?

Mesquite species that are weeds in Australia are natives of Central America, northern South America and southern North America (CRC 2003).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?


Where is it a declared weed?


Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?


Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?


Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Prosopis spp.

Other scientific names (synonyms)?

  • Neltuma Raf.
  • Sopropis Britton & Ros
  • Strombocarpa (Benth.) A.Gray
  • Algarobia (DC.) Benth.

Does it have other known common name(s)?


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