Quick Facts

Quick facts

• Spotted Thistle (Scolymus maculatus) is a yellow flowered annual herb with a dark skinned parsnip like tap root and spiny leaves.
• Livestock do not eat it due to the spines.
• The leaves, stalks and seeds can contaminate wool.
• It is a threat to agricultural production due to the ability to form thick impenetrable clumps.
• Management requires manual removal or slashing prior to flowering with herbicide used on large or difficult infestations.

What Does It Look Like?

What is it?

Spotted Thistle (Scolymus maculatus) is an upright branching annual herb which grows 50 to 100 cm tall. It has a dark skinned parsnip like tap root which can grow to 60 cm long and 10 cm wide with fibrous roots. There are two distinct types of leaves. The leaves up the stems are alternate and spiny with a broad leaf base which extends down the stem in a wing. The rosette leaves are shortly stalked with spiny tips. Both are shiny green with white spots and white margins.

The golden yellow flowers occur at the end of the stem. They are about 2.5 cm in diameter and often ringed by spiny bracts between 11 and 18 mm long.

The seed (achene) is yellow brown, 4 to 5 mm long and enclosed by laterally winged scales (INRA 2000, Parsons & Cuthbertson 2001).

For further information and assistance with identification of Spotted Thistle contact the herbarium in your state or territory.

Flower colour

Yellow

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

Spotted Thistle prefers subhumid warm temperate regions with winter rainfall. It can tolerate drought and frosts and is often found on heavy clay soils. Spotted Thistle, along with Golden Thistle (Scolymus hispanicus), is considered a weed of pasture, wasteland and disturbed areas and is common along roadsides (Cunningham et al. 1981; Aulde & Medd 1987; Nuez & Hernández Bermejo 1994; Parsons & Cuthbertson 2001).

Are there similar species?

Although not commonly mistaken for each other, Spotted Thistle is similar to Golden Thistle (Scolymus hispanicus). Golden Thistle is a perennial, rather than an annual, and is without the bony thick margins on the leaves (Auld & Medd 1987).

Why Is It A Weed?

What are its impacts?

Agriculture: Agricultural impacts of Spotted Thistle include the contamination of wool by dead plant material and seed as well as the loss of grazing land. Grazing land is reduced through the formation of spiny impenetrable clumps which exclude activities and stock from areas (Parsons & Cuthbertson 2001).

Native ecosystems: Spotted Thistle impacts on the environment by providing cover for feral animals, such as rabbits, through the formation of spiny impenetrable clumps (Parsons & Cuthbertson 2001). The environmental impacts of rabbits include completion with native wildlife, damage to native vegetation and erosion of the soil (DEH 2004).

How does it spread?

Spotted Thistle is dispersed predominantly by wind. The above ground section becomes brittle and breaks loose at the base. The wind then cartwheels it along the ground shaking seeds out as it moves. Sheep and livestock can also transport seeds in their wool and fur (Parsons & Cuthbertson 2001).

What is its history in Australia?

Spotted Thistle was known along the stock route from Breeza through Warrah and Merriwa in New South Wales in the late 1800s. The first recorded naturalisation was in Murrurundi, New South Wales, in 1908 (Parsons & Cuthbertson 2001).

There is no clear indication of how or why this species was introduced but it was known to be an ornamental plant in England during the seventeenth century as well as a traditional food plant of the Mediterranean region (Nuez & Hernández Bermejo 1994; Parsons & Cuthbertson 2001).

How To Manage It?

Best practice management

Non-chemical control: Physical control: Small infestations of Spotted Thistle can be controlled through manual removal (grubbing) before the flowers emerge. Mechanical control: Cropping or slashing can be effective if carried out prior to flowering as well as consistently over a number of years to remove successive seed germinations.

Chemical control: The use of herbicide via a boom spray is the best method of control large outbreaks or infestations on difficult terrain (Parsons & Cuthbertson 2001).

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au .

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Seeds of Spotted Thistle germinate in autumn and early winter. The taproot develops slowly with the branching stems forming in late winter. Spotted Thistle flowers in November and December (Parsons & Cuthbertson 2001).

Where Is It Found?

Which states and territories is it found?

NSW

What areas within states and territories is it found?

Spotted Thistle is distributed mainly in the north and north western areas of New South Wales (Parsons & Cuthbertson 2001).

Where does it originate?

Spotted Thistle is native to the Mediterranean region (Parsons & Cuthbertson 2001).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

NSW, WA

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Scolymus maculatus

Other scientific names (synonyms)?

Does it have other known common name(s)?

Spotted Golden Thistle, Shawkat-al-far (Lebanon)