Parkinsonia (Parkinsonia aculeata)

Also known as: Jerusalem thorn

Profile

Impact

Parkinsonia is an invasive spiny shrub or small tree that forms impenetrable dense thickets around watercourses such as drainage lines, creeks, dams, rivers and bores - leading to reduced water flow and availability of surface water, erosion and loss of native habitat. Infestations can also restrict access to land and waterways, degrade pasture, replace native plant species and provide shelter for feral animals.It is adapted to a range of climates and once established is capable of withstanding long periods of heat and drought. 

Distribution

Parkinsonia is native to Central America, the Caribbean, southern USA, Mexico and northern South America.

It has been introduced to many parts of the world and has become an invasive weed of South Africa, the Mediterranean, tropical Africa, south-western Asia, India and the Pacific Islands. Parkinsonia has also become invasive in parts of its native range including Mexico and southern USA.

Originally introduced to Australia in the late 1800s as a shade and ornamental tree, parkinsonia has now naturalised throughout most of northern Australia. The largest infestations occur in Queensland, the Northern Territory and northern Western Australia. Small isolated infestations have occurred in South Australia.

In New South Wales (NSW), isolated infestations have been identified in Broken Hill, Walgett, Bourke and the far north western corner of the state. Parkinsonia has the potential to invade the north and central coastal regions and most of western NSW.

Distribution map

Spread

Parkinsonia reproduces by seed. Water movement is responsible for most of its spread as seed pods can float and be carried large distances by floodwaters.

A mature tree usually produces around 5000 seeds per year. Seeds have a hard, thick coat and can remain dormant in the soil for a number of years. Dormancy is normally broken by wet and warm to hot conditions, and is then usually followed by a mass germination event.

Spread can also occur through movement of contaminated sand or soil from infested sites.

Description

Parkinsonia is a single- or multi-stemmed shrub or small tree that can grow up to 8 m high.

Key identification features

  • Stems are green, smooth and slender, slightly zig-zagged and drooping.
  • Each leaf stalk is green and flat, up to 30 cm long and 2–3 mm wide, with many small (4–10 mm) oblong leaflets staggered along each side.
  • Spines are sharp, 5–15 mm long and grow from the leaf nodes.
  • Fragrant flowers are about 2 cm across and 5-petalled, with four petals yellow and one erect orange or orange-spotted petal. Each flower stalk is 5–20 cm long and has 8–12 flowers.
  • Seed pods are hairless, up to 10 cm long, leathery and straw-coloured when ripe. They are straight with pointy ends and have constrictions between the seeds. Each pod usually contains 1–4 seeds, but occasionally up to 11.
  • Seeds are oblong, 8–10 mm long and olive to brown in colour.

Habitat

Parkinsonia grows well on open grasslands and rangelands, although wetlands and floodplains are particularly vulnerable to invasion.

Acknowledgements

Adapted from CRC Weed Management Guide (2003) Parkinsonia (Parkinsonia aculeata)

Reviewed by: Peter Gray; Edited by: Elissa van Oosterhout

References

Hosking JR, Sainty GR, Jacobs SWL & Dellow LL (in prep) The Australian WeedBOOK

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Control

If you suspect you have found parkinsonia you should contact your local council weeds officer who will assist with identification, removal and eradication.

A range of control options are available for parkinsonia. A suitable control program should be tailored to suit the landscape and size of the infestation.

Herbicide options

WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au

See Using herbicides for more information.


Hexazinone 250 g/L (Velpar® L)
Rate: 4 mL per spot
Comments: One spot per bush up to 5 m tall.
Withholding period: No stated withholding period.
Herbicide group: C, Inhibitors of photosynthesis at photosystem II (PS II inhibitors)
Resistance risk: Moderate


Hexazinone 250 g/L (Velpar® L)
Rate: 1 mL per spot
Comments: One spot per bush up to 1 m tall. Do not use near desirable plants.
Withholding period: No stated withholding period.
Herbicide group: C, Inhibitors of photosynthesis at photosystem II (PS II inhibitors)
Resistance risk: Moderate


Picloram 44.7 g/kg + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump/stem injection application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 240 g/L + Picloram 120 g/L (Access™ )
Rate: 1.0 L in 60 L of diesel
Comments: Basal bark or cut stump application.
Withholding period: Nil
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


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Biosecurity duty

The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.

Area Duty
All of NSW General Biosecurity Duty
All plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable.
All of NSW Mandatory Measure
Must not be imported into the State or sold
All of NSW
Parkinsonia Control Zone: Whole of NSW
Biosecurity Control Order
Parkinsonia Control Zone (Whole of NSW): Owners and occupiers of land on which there is parkinsonia must notify the local control authority of new infestations; immediately destroy the plants; ensure subsequent generations are destroyed; and ensure the land is kept free of the plant. A person who deals with a carrier of parkinsonia must ensure the plant (and any seed and propagules) is not moved from the land; and immediately notify the local control authority of the presence of the plant.

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For technical advice and assistance with identification please contact your local council weeds officer.
For further information call the NSW Invasive Plants and Animals Enquiry Line on 1800 680 244 or send an email to weeds@dpi.nsw.gov.au

Reviewed 2017