Carduus acanthoides

Plumeless thistle

Also known as:

Bastard nodding thistle, tapapa thistle, welted thistle

Family: Asteraceae

Origin: Eurasia

A bush of plumeless thistle in a dry field.
Has a large tap root that can remove key nutrients from the soil, degrading agricultural land. Can survive in very harsh conditions where other pasture plants cannot.
Photo credit: Todd Pfeiffer, Klamath County Weed Control,

Regional Pest Management Plan (RPMP) status

  • Whole region — Sustained control
  • Hauraki Gulf Controlled Area Notice pest

View more about the RPMP statuses

General description

Biennial or annual thistle < 2.5 m tall. Stems are erect and winged. Leaves are narrow, deeply divided and form flat rosette. Stems and leaves are spiny and sometimes woolly. Inflorescences are purple and borne at the end of the stems. Achenes bear pappus.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell plumeless thistle within the Auckland region.
  • You must not plant plumeless thistle within the Auckland region, unless you are transferring an existing plant on your land to another location within the boundaries of the same property.
  • You must destroy any plumeless thistle on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person.


Roadsides, fields, wasteland, disturbed sites, pasture.


Seeds dispersed by wind.

Impact on environment

Aggressively infests pastures, reducing forage quality and accessibility to stock. Spines can cause injuries to humans and livestock.


Site Management

Maintaining good pasture cover can prevent establishment or suppress an infestation. Prevent overgrazing especially in summer. Other herbicides are available for selective use in pasture.

Recommended approaches

Physical control

Method: Dig or grub out at least the first 5cm of taproot.

Plant parts requiring disposal: Seeds.

Disposal options: Remove to greenwaste or landfill if practical.


Check for presence of agents for nodding thistle which also attack plumeless thistle:

  • Nodding thistle receptacle weevil (Rhinocyllus conicus)
  • Nodding thistle gall fly (Urophora solstitalis)
  • Nodding thistle crown weevil (Trichosirocalus horridus)

For more information about how biocontrol works, see What is biocontrol?

Community agrichemical control recommendations

No qualifications: Foliar spray with 100ml glyphosate green per 10L of water.

Certified Handler/Experienced agrichemical user: Foliar spray with 100ml glyphosate green per 10L of water and 20ml penetrant.

Safety notes

Plant has spines.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

A purple flower at the tip of the plumeless thistle.
A thistle that can grow up to 2.5m tall and can grow for one year or up to two. Stems, leaves and flower buds are covered in sharp spikes that hurt when touched.
Close up of plumeless thistle growing in a field.
A very hardy plant that loves open pasture grass. Not eaten by stock due to the sharp prickles so has the ability to take over paddocks.
Photo credit: Todd Pfeiffer, Klamath County Weed Control,
A young Plumeless Thistle
Flowers are pinky purple, and seeds are small and black. Seeds are borne on white fluff that can carry seeds on the wind into new pasture areas.
Close up of plumeless thistle leaf.
Best controlled by grubbing out and removing the top of the tap root. Chemical control should only be used when the plant is young can cannot form flowers.
Photo credit: Todd Pfeiffer, Klamath County Weed Control,