Carthamus lanatus

Saffron thistle

Also known as:

Woolly distaff thistle, downy safflower

Family: Asteraceae

Origin: Eurasia

Close up on the prickly saffron thistle.
Flowers are yellow with purple veins and produce prickles below the flower itself. A herb that grows up to 1m tall and can live for one year or up to two.
Photo credit: Trevor James, AgResearch

Regional Pest Management Plan (RPMP) status

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

View more about the RPMP statuses

General description

Upright, annual or biennial herb < 1 m tall. Taproot is shallow. Stems arise from rosette and are woody, initially single and then branching. Leaves are glossy, dark green and spiny. Flowers are yellow with purplish veins and bear a bract of prickles below. Achenes bear pappus.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell saffron thistle within the Auckland region.
  • You must not plant saffron 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 saffron 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.

Habitats

Pasture, wasteland, open or disturbed sites.

Dispersal

Seeds dispersed by gravity, wind and attachment to livestock.

Impact on environment

Competes with desirable pasture species, impedes stock movement and injures grazing animals. Unpalatable to stock. Competes with crops and impedes harvesting equipment. Likely to be a reservoir of crop pathogens.

Control

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.

Biocontrol

Biocontrol is currently not available for this species.

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.

Close up on saffron thistle leaves.
Initially its leaves are glossy and dark green but eventually dry out and become very spikey as it matures. Tends to grow in paddocks and competes with grass growth.
Photo credit: Trevor James, AgResearch
Saffron thistle with a flower right at the top.
Has noticeable bright yellow flowers that grow at the top of the plants stems. The leaves are hard and spiky.
Photo credit: Trevor James, AgResearch
A saffron thistle growing tall in a field.
A tall herb less than 1m in height. Found in dry areas of pasture, flats and hillsides.
Photo credit: Trevor James, AgResearch