Devil's claw - purple-flowered (Proboscidea louisianica)

Purple-flowered devil’s claw is an annual plant that produces seed capsules with ‘claws’ that attach to animals and vehicles. The seed capsules can injure or kill livestock.

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How does this weed affect you?

Purple-flowered devil’s claw:

• invades pastures and reduces productivity
• competes with summer crops such as cotton.

The seed capsules have two long curved claws on the end that stick to livestock causing:

• restricted feeding when attached to animals faces, eventually causing starvation
• lameness when attached to hooves
• reduced wool quality when caught in fleeces
• damage to wool shears. 

What does it look like?

Purple-flowered devil’s claw is an annual plant that grows to 50 cm tall. It grows quickly in spring and summer and then dies in autumn.

Leaves are:

• 10–16 cm long and 14–25 cm wide
• rounded with a heart-shaped base
• hairy 
• opposite along the stem
• on stalks up to 16 cm long.

Flowers are:

• creamy-white to mauve or purple
• with dark purple or orange markings
• trumpet-shaped
• in loose clusters
• present in summer though to autumn.

Fruit are:

• capsules containing many seeds
• fleshy at first becoming woody
• 8–10 cm long and 1–2 cm wide with two curved claws 10–25 cm long
• split into two, each half having a curved claw when mature and dry.

Seeds are:

• black or grey
• 10 mm long and 6 mm wide
• wrinkled and a variety of shapes.

Stems are:

• erect
• branched
• hollow
• covered with sticky hairs.

Similar looking plants

Purple flowered devil’s claw looks like:

• yellow-flowered devil's claw (Ibicella lutea), which have yellow flowers, and the claws are longer.
• some varieties of pumpkins (Cucurbita pepo), which have lobed leaves (3-5 lobes), yellow flowers and the pumpkin fruit look very different.

Where is it found?

In NSW most purple-flowered devil's claw grows west of the dividing ranges. Plants have been found in the Riverina, North West, Central West, Murray and Western regions. It was introduced as an ornamental plant.

It is native to America.

What type of environment does it grow in?

Purple-flowered devil’s claw grows in temperate and tropical regions. It can grow in full sun or shade and is mostly found in fertile soils. It is very drought tolerant and grows in disturbed areas including:

• in cultivated areas
• in degraded or drought affected pastures
• along roadsides
• on river flats.

How does it spread?

Purple-flowered devil’s claw only reproduces by seed It can produce up to 122 capsules per plant with up to 71 seeds in each capsule.

The ‘claws’ on the seed capsules attach to animals, clothing, machinery or vehicles and can be transported long distances.

References

Bryson, C. T., Koger, C. H., & Byrd Jr, J. D. BIOLOGY AND ECOLOGY OF YELLOW UNICORN-PLANT (IBICELLA LUTEA). Retrieved 4 March 2021 from: https://www.ars.usda.gov/ARSUserFiles/64022000/Posters/2004/2004_SWSS_CTB.pdf

Department of Agriculture, Water and the Environment. (2011). Weeds in Australia. Ibicella lutea. Australian Government. Retrieved 31 March 2020 from: https://www.environment.gov.au/cgi-bin/biodiversity/invasive/weeds/weeddetails.pl?taxon_id=14683#

Parsons, W. T., & Cuthbertson, E. G. (2001). Noxious weeds of Australia. (2nd Edition). CSIRO publishing.

PlantNET (The NSW Plant Information Network System).Proboscidea louisianica (Mill.) Thell. Royal Botanic Gardens and Domain Trust, Sydney. Retrieved from 23 March 2020 from: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Proboscidea~louisianica

Richardson, F.J., Richardson R.G. & Shepherd, R.C.H. (2011) Weeds of the South-East: An Identification Guide. 2nd Edition.  R.G. & F.J. Richardson Meridith Vic.

More information

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Control

Successful weed control relies on follow up after the initial efforts. This means looking for and killing regrowth or new seedlings. Using a combination of control methods is usually more successful.

To manage purple-flowered devil’s claw:

• treat plants before fruit are produced whenever possible
• manual control before flowering is effective 
• burn plants that are removed after flowering.

Physical removal

By hand

When: Before flowers appear is the best time.

Hand-pulling and hoeing are effective because roots left in the ground will not regrow. If fruit or flowers are present, dispose of them carefully. The fruit can form from flowers after the plants have been cut.

Cultivation

When: Before flowers appear so that the seeds are not spread.

Cultivation usually kills young plants.

Disposal

Burn any plants removed after flowering to prevent seed development. Contact your local council for alternative disposal methods.

Chemical control

Spray when the plant is actively growing before the pods form.

Herbicide options

See Using herbicides for more information.

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2,4-D LV ester 680g/L (Estercide® Xtra)
Rate: 1.15 to 1.7 L per ha
Comments: Boom spray application, before pods form. For non-legume pastures.
Withholding period: Do not graze or cut for stock food for 7 days after application.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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Biosecurity duty

The content provided here is for information purposes only and is taken from the NSW 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 pest 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.

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Reviewed 2024