King devil hawkweed (Pilosella piloselloides)

King devil hawkweed is a perennial herb with yellow daisy like flowers and hairy leaves. It outcompetes native plants and pastures in alpine and cool temperate regions.

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How does this weed affect you?

King devil hawkweed forms dense stands with thousands of plants per square metre. It is a significant threat to biodiversity in the alpine regions in Australia. It can:

• outcompete native plants, especially native grasses in alpine regions
• reduce food and habitat for native animals
• compete with pastures and reduce grazing productivity.

What does it look like?

King devil hawkweed is a perennial herb that grows up 75 cm tall. Milky sap is released when the when the stems or leaves are broken. The only subspecies found in Australia is Pilosella piloselloides subsp. bauhinii. The following description is for this subspecies. 

Leaves are: 

• at the base of the plant in a rosette (growing out from one central point)
• also along the stolons and sometimes 1-4 on the lower part of the flower stem 
• bluish-green on top 
• 1.5–20 cm long and 0.5–3 cm wide 
• lance or egg-shaped and narrow at the base
• either smooth or slightly toothed along the edges 
• covered in long blackish hairs 
• stalkless. 

Flowers are: 

• bright yellow 
• daisy-like with square ended petals 
• 1–2 cm in diameter 
• covered in black hairs on the bracts at the base of the flowerhead 
• in tight clusters of 3-35 on branched stems 
• present in summer. 

Flower stems are: 

• up to 30 cm long 
• covered in short, stiff hairs. 

Seeds are: 

• dark brown to purplish black 
• cylindrical and tapered 
• ribbed 
• 2 mm long with a short whitish pappus. 

Similar looking plants 

King devil hawkweed looks similar to: 

• Mouse-ear hawkweed (Pilosella officinarum), which is much shorter and only has one yellow flower per stem.  
• Wall hawkweed (Hieracium murorum), which has leaves on stalks up to 4 cm long. 
• Dandelions (Taraxacum officinale), which often have deeply divided leaves up to 35 cm long, and only one yellow flower per stem. 
• Flatweeds (Hypochaeris species), which have one flowerhead per branched hairless stem. 

Where is it found?

King devil hawkweed has not been found in NSW. It is present in Victoria.

It is native to Europe and Asia.

What type of environment does it grow in?

King devil hawkweed is frost tolerant and can grow on a wide range of soil types. It prefers cool climates with an annual rainfall above 500 mm. Plants are most likely to sprout on disturbed sites with moist soils.

Maps and records

• Recorded presence of King devil hawkweed during property inspections (Map: Biosecurity Information System - Weeds, 2017-2024)
  These records are made by authorised officers during property inspections under the Biosecurity Act 2015. Officers record the presence of priority weeds in their council area and provide this to the NSW Department of Primary Industries. Records reflect the presence of the weed on the date of inspection.
  
  

How does it spread?

King devil hawkweed can produce over 240 seeds per stem. Seeds have high viability and most seeds germinate in summer. Some seeds may remain viable in the soil for up to 5 years but most seed germinate within a month on the soil surface. The seeds have tufts of hairs that mean they can be blown by the wind but the average distance travelled is only 2.6 m from the parent plant. Occasionally seeds may be blown over 1 km from the parent plant. Seeds are also spread by: 

• water 
• sticking to boots, clothing and camping or other recreational equipment 
• attaching to animals 
• vehicles, ski machinery or slashers 
• contaminated seed. 

References

Cousens, R. D., & Williams, N. (2011). Improved detection and eradication of hawkweed (Hieracium). Rural Industries Research and Development Corporation.

VicFlora (2022). Flora of Victoria, Royal Botanic Gardens Victoria. Retrieved 21 September 2022 from: https://vicflora.rbg.vic.gov.au 

Williams, N.S.G. and Holland, K.D. (2007). The ecology and invasion history of hawkweeds (Hieracium species) in Australia, Plant Protection Quarterly, 22(2): 76-80

More information

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Control

Please do not attempt to treat or dispose of this weed yourself. Report this plant if you see it anywhere in NSW by calling the helpline listed at the top of this page immediately.

NSW DPI will lead an initial response for the treatment and disposal of the plant to stop it from spreading.

Herbicide options

See Using herbicides for more information.

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PERMIT 14558 Expires 30/06/2024
Clopyralid 300 g/L (Lontrel®)
Rate: 5 mL in 1 L of water
Comments: Spot spray application only for National Parks and non-agricultural adjoining lands. Only for use by NPWS employees and contractors, See permit for further critical comments.
Withholding period: 1-12 weeks (see label).
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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PERMIT 14928 Expires 30/09/2024
Picloram 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L (Grazon Extra®)
Rate: 250-500 mL per 100 L plus BS 1000 or equivalent at 100 mL per 100 L
Comments: Spray actively growing plants before flowering. Do not apply more than once per season. See permit for critical comments.
Withholding period: Where product is used to control woody weeds in pastures there is a restriction of 12 weeks for use of treated pastures for making hay and silage; using hay or other plant material for compost, mulch or mushroom substrate; or using animal waste from animals grazing on treated pastures for compost, mulching, or spreading on pasture/crops.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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PERMIT 14928 Expires 30/09/2024
Triclopyr 300 g/L + Picloram 100 g/L (Various products)
Rate: 250-500 mL per 100 L plus BS 1000 or equivalent at 100 mL per 100 L
Comments: Spray actively growing plants before flowering. Do not apply more than once per season. See permit for critical comments.
Withholding period: Nil.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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PERMIT 14301 Expires 31/07/2026
Picloram 20 g/kg (Tordon® Granules)
Rate: 45 g/m2
Comments: Granular application only in Kosciuszko National Park and lands in the Snowy Monaro Regional Council area. See permit for further critical comments.
Withholding period: Nil.
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 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.
All of NSW	Prohibited Matter A person who deals with prohibited matter or a carrier of prohibited matter is guilty of an offence. A person who becomes aware of or suspects the presence of prohibited matter must immediately notify the Department of Primary Industries All species in the genus Pilosella are Prohibited Matter

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Reviewed 2024