Wall hawkweed (Hieracium murorum)
Wall hawkweed is a perennial herb up to 70 cm tall with yellow daisy-like flowers. It competes with native plants and pastures.
This weed belongs to the group Hawkweeds - Hieraciums
Profile
How does this weed affect you?
Wall hawkweed can form dense mats across the ground that:
- outcompete native plants including threatened species and plants in ecologically endangered ecosystems
- reduce habitat and food for native animals
- can take over pastures, gardens and native grasslands.
What does it look like?
Wall hawkweed is a perennial herb that grows up to 70 cm tall. Milky sap is released when the when the stems or leaves are broken. Unlike other hawkweeds in Australia, wall hawkweed does not have stolons.
Leaves are:
- in a rosette (all growing out from a central point) at the base of the plant
- sometimes present near the base of the flower stem
- dark green often purple mottled and the upper surface darker than lower
- 5–11 cm long and 2.5–4.5 cm wide
- oval or spoon shaped and toothed along the margins
- on stalks up to 4 cm long
- hairy with long white hairs on both sides but denser on the underside, veins and margins.
Flowers are:
- bright yellow
- daisy-like with petals that have 5 teeth at the end
- 2–5 cm in diameter
- in clusters of 5–8
- present from October to April.
Seeds are:
- black
- ribbed
- 3 mm long with a whitish pappus.
Flower stems are:
- either hairless or sparsely hairy.
Roots are:
- a woody taproot with fibrous roots
- short and thick.
Similar looking plants
Wall hawkweed looks similar to:
- Mouse-ear hawkweed (Pilosella officinarum), which is much shorter and only has one yellow flower per stem. It also has no stalks on the leaves.
- King devil hawkweed (Pilosella piloselloides), which has no stalks on the leaves.
- Dandelions (Taraxacum officinale), which have leaves up to 35 cm long that are often deeply divided and only one yellow flower per stem.
- Flatweeds (Hypochaeris species), which have one flowerhead per branched hairless stem.
Where is it found?
In NSW, wall hawkweed was found in Katoomba in 1998 and Mount Irvine in 2006.
It is native to western Asia and Europe.
What type of environment does it grow in?
Wall 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 often found in areas where the soil has been disturbed.
How does it spread?
Wall hawkweed plants can mature and start producing seeds in approximately 5 months. The seeds have tufts that help the seed attach to hair, fur, and vehicles. Seeds can be spread by:
- wind and water
- sticking to boots, clothing and camping or other recreational equipment
- attaching to animals
- vehicles, ski machinery or slashers.
References
Healy, A. J. (1962). Dandelions and related rosette weeds in New Zealand. In Proceedings of the New Zealand Weed Control Conference (Vol. 15, pp. 53-85).
PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 22 September 2022 from: https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Hieracium~murorum
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
Wilson, L. M. (2006). Key to Identification of Invasive and Native Hawkweeds (Hieracium Supp.) in the Pacific Northwest. British Columbia, Ministry of Forests and Range, Forest Practices Branch, Invasive Alien Plant Program.
More information
Control
Wall hawkweed looks similar to other species of hawkweed that are prohibited matter in NSW. Contact your local council weeds officer to help identify any hawkweed plants.
Prevention
Hawkweed seeds can be spread by recreational activities. Ensure that you thoroughly clean boots, clothing and equipment before both entering and leaving National Parks or infested sites.
Physical control
Seedlings can be pulled out and small infestations can be dug out by hand.
Spraying
Spray actively growing plants before flowering. Thoroughly cover all of the leaves with the herbicide mix.
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
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.
PERMIT 14928 Expires 30/09/2024
Picloram 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L
(Grazon Extra®)
Rate: Rate: 25-50 mL per 10 L of water per 100 meter squared plus BS 1000 or equivalent at 10 mL per 10 L of water
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
PERMIT 14928 Expires 30/09/2024
Triclopyr 300 g/L + Picloram 100 g/L
(Various products)
Rate: 25-50 mL in 10 L water per 100 m2 Plus BS 1000 or equivalent at 10 mL per 10 L of water
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
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. |
For technical advice and assistance with identification please contact your local council weeds officer.
Reviewed 2023
