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Prickly Sow-thistle

Sonchus asper

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Plant Profile

Flowering Months:
Asteraceae (Daisy)
Also in this family:
Alpine Blue Sow-thistle, Alpine Cotula, Alpine Fleabane, Alpine Saw-wort, Annual Ragweed, Annual Sunflower, Argentine Fleabane, Autumn Hawkbit, Autumn Oxeye, Beaked Hawksbeard, Beggarticks, Bilbao Fleabane, Black Knapweed, Black-eyed Susan, Blanketflower, Blue Fleabane, Blue Globe-thistle, Bristly Oxtongue, Broad-leaved Cudweed, Broad-leaved Ragwort, Brown Knapweed, Butterbur, Buttonweed, Cabbage Thistle, Canadian Fleabane, Canadian Goldenrod, Carline Thistle, Chalk Knapweed, Chamois Ragwort, Changing Michaelmas Daisy, Chicory, Chinese Mugwort, Chinese Ragwort, Coltsfoot, Common Blue Sow-thistle, Common Cat's-ear, Common Cudweed, Common Daisy, Common Dandelion, Common Fleabane, Common Goldenrod, Common Groundsel, Common Michaelmas Daisy, Common Mugwort, Common Ragwort, Common Wormwood, Coneflower, Confused Michaelmas Daisy, Corn Chamomile, Corn Marigold, Cornflower, Cotton Thistle, Cottonweed, Creeping Thistle, Daisy Bush, Dwarf Cudweed, Dwarf Thistle, Early Goldenrod, Eastern Groundsel, Eastern Leopardsbane, Elecampane, English Hawkweed, Fen Ragwort, Feverfew, Field Fleawort, Field Wormwood, Fox and Cubs, French Tarragon, Gallant Soldier, Garden Lettuce, Giant Butterbur, Glabrous-headed Hawkweed, Glandular Globe-thistle, Glaucous Michaelmas Daisy, Globe Artichoke, Globe-thistle, Goat's Beard, Golden Ragwort, Golden Samphire, Goldilocks Aster, Grass-leaved Goldenrod, Great Lettuce, Greater Burdock, Greater Knapweed, Grey-headed Hawkweed, Guernsey Fleabane, Hairless Blue Sow-thistle, Hairless Leptinella, Hairy Michaelmas Daisy, Harpur Crewe's Leopardsbane, Hawkweed Oxtongue, Heath Cudweed, Heath Groundsel, Hemp Agrimony, Highland Cudweed, Hoary Mugwort, Hoary Ragwort, Hybrid Knapweed, Intermediate Burdock, Irish Fleabane, Jersey Cudweed, Jerusalem Artichoke, Lance-leaved Hawkweed, Lavender-cotton, Leafless Hawksbeard, Least Lettuce, Leopardplant, Leopardsbane, Leptinella, Lesser Burdock, Lesser Hawkbit, Lesser Sunflower, London Bur-marigold, Magellan Ragwort, Marsh Cudweed, Marsh Hawksbeard, Marsh Ragwort, Marsh Sow-thistle, Marsh Thistle, Meadow Thistle, Melancholy Thistle, Mexican Fleabane, Milk Thistle, Mountain Everlasting, Mouse-ear Hawkweed, Musk Thistle, Narrow-leaved Cudweed, Narrow-leaved Hawkweed, Narrow-leaved Michaelmas Daisy, Narrow-leaved Ragwort, New England Hawkweed, New Zealand Holly, Nipplewort, Nodding Bur-marigold, Northern Hawksbeard, Norwegian Mugwort, Oxeye Daisy, Oxford Ragwort, Pearly Everlasting, Perennial Cornflower, Perennial Ragweed, Perennial Sow-thistle, Perennial Sunflower, Pineapple Mayweed, Plantain-leaved Leopardsbane, Ploughman's Spikenard, Plymouth Thistle, Pontic Blue Sow-thistle, Pot Marigold, Prickly Lettuce, Purple Coltsfoot, Rayed Tansy, Red Star Thistle, Red-seeded Dandelion, Red-tipped Cudweed, Robin's Plantain, Roman Chamomile, Rough Cocklebur, Rough Hawkbit, Rough Hawksbeard, Russian Lettuce, Safflower, Salsify, Saw-wort, Scented Mayweed, Scentless Mayweed, Sea Aster, Sea Mayweed, Sea Wormwood, Seaside Daisy, Shaggy Mouse-ear Hawkweed, Shaggy Soldier, Shasta Daisy, Shetland Mouse-ear Hawkweed, Shrub Ragwort, Sicilian Chamomile, Silver Ragwort, Slender Mugwort, Slender Thistle, Small Cudweed, Small Fleabane, Smooth Cat's-ear, Smooth Hawksbeard, Smooth Sow-thistle, Sneezeweed, Sneezewort, Spear Thistle, Spotted Cat's-ear, Spotted Hawkweed, Sticky Groundsel, Stinking Chamomile, Stinking Hawksbeard, Tall Fleabane, Tall Mouse-ear Hawkweed, Tansy, Thin-leaved Sunflower, Treasureflower, Trifid Bur-marigold, Tuberous Thistle, Tyneside Leopardplant, Viper's Grass, Wall Lettuce, Welsh Groundsel, Welted Thistle, White African Daisy, White Butterbur, White Buttons, Willdenow's Leopardsbane, Winter Heliotrope, Wood Burdock, Wood Ragwort, Woody Fleabane, Woolly Thistle, Yarrow, Yellow Chamomile, Yellow Fox and Cubs, Yellow Oxeye, Yellow Star Thistle, Yellow Thistle, York Groundsel
Life Cycle:
Maximum Size:
150 centimetres tall
Fields, gardens, grassland, meadows, roadsides, rocky places, towns, walls, wasteland, waterside.

Yellow, many petals
Large yellow dandelion-like flowers.
Smooth, ribbed achenes (seeds).
Leathery and stiff leaves with prickly margins. The upper leaves are shiny and clasp their stems. The basal lobes of the leaves are rounded. Sparsely haired. The leaves are up to 25cm (10 inches) long.
Other Names:
Rough Milk Thistle, Rough Sow-thistle, Sharp-fringed Sow-thistle, Spiny Annual Sow-thistle, Spiny Sow-thistle, Spiny-leaved Sow-thistle.
Frequency (UK):

Other Information


Sonchus asper, also known as "spiny sowthistle" or "prickly sowthistle," is a perennial herb that is native to Europe and Asia. It is a hardy plant that can grow in a variety of soil types and can tolerate shade and dry conditions. It can be found in grasslands, meadows, along roadsides and in croplands. It is considered as a weed in some regions, and it can be difficult to control as it reproduces both by seed and underground rhizomes. The plant has large leaves and yellow flowers that can reach up to 3-5 feet tall. The stem, leaves and bracts are covered with spines, hence the name "spiny sowthistle". The leaves and flowers are edible, but they are not commonly used as food. It has been used in traditional medicine to treat various ailments such as skin irritations and infections.


Prickly Sow-thistle, or Sonchus asper, is a plant species that is native to Europe and Western Asia but has become naturalized in many other parts of the world, including North America, South America, Africa, and Australia. This plant belongs to the Asteraceae family, which includes other well-known species such as daisies and sunflowers. The prickly sow-thistle gets its name from the spiny edges on its leaves and stems.

Physical Characteristics

The prickly sow-thistle can grow up to 5 feet tall and has a distinctive yellow flower head that resembles a dandelion. Its stem and leaves are covered in prickly spines, which make it difficult to handle without protection. The leaves of this plant are green and lanceolate, with irregularly lobed margins. The prickly sow-thistle has a shallow root system and can grow in a wide range of soil types, including sandy and loamy soils.


Despite its spiny and prickly nature, the prickly sow-thistle has several uses. It is sometimes used as a food source, with the leaves being used in salads or cooked as a vegetable. In some cultures, the prickly sow-thistle is considered a medicinal plant and is used to treat a range of ailments, such as liver disorders and digestive issues. The plant contains several beneficial compounds, including antioxidants, flavonoids, and alkaloids, which may contribute to its medicinal properties.

Ecological Impacts

Prickly sow-thistle is considered an invasive species in some areas, including the United States. It can grow rapidly and outcompete native plants for resources such as water, light, and nutrients, which can have a negative impact on the local ecosystem. In addition, the plant can hybridize with other Sonchus species, creating hybrids that may have different ecological impacts.

Control Measures

Controlling the spread of the prickly sow-thistle can be challenging, as it has a shallow root system and can quickly regrow from even small fragments of the plant. Manual removal, including digging up the plant by the root, is often effective, but it must be done thoroughly to prevent regrowth. Chemical control methods can also be used, but care must be taken to ensure that other plants are not affected. Preventing the spread of prickly sow-thistle can be achieved by taking steps to limit its spread, such as avoiding movement of soil or plant material from infested areas.

The prickly sow-thistle is a fascinating plant species that has both positive and negative impacts. While it can be used as a food source and has medicinal properties, it can also be an invasive species that can negatively impact the local ecosystem. Understanding the characteristics of this plant can help individuals to effectively control its spread and protect native species from its negative impacts.

Ecological Impacts

The prickly sow-thistle has a wide ecological amplitude, meaning that it can grow in a variety of habitats and soil types, including disturbed areas such as roadsides, agricultural fields, and construction sites. This adaptability makes it a successful colonizer of new areas, and it can quickly form dense monocultures that outcompete native plants. The prickly sow-thistle's prolific seed production also makes it difficult to control, as a single plant can produce hundreds of seeds that can remain viable in the soil for many years.

The impact of prickly sow-thistle on local ecosystems can be significant. Its rapid growth can lead to shading of other plant species, reducing their ability to photosynthesize and grow. The plant's shallow root system also means that it can reduce soil stability and contribute to erosion, which can further impact the local ecosystem. In addition, the prickly sow-thistle can serve as a host for a range of pests and diseases, potentially increasing the spread of these problems to other plant species.

Further Control Measures

There are several strategies that can be used to control the spread of prickly sow-thistle. One effective method is to manually remove the plant by hand or using mechanical means such as digging it up or cutting it down. This method is most effective when carried out before the plant has had a chance to produce seeds. Chemical control can also be effective, but it is important to use the right herbicide at the right time, as some herbicides are more effective on young plants, while others are more effective on mature plants.

Preventive measures can also be taken to limit the spread of prickly sow-thistle. These include avoiding the introduction of soil or plant material from infested areas, and carefully cleaning any equipment that may have come into contact with the plant. In addition, promoting the growth of native plant species can help to limit the ability of prickly sow-thistle to colonize an area.

The prickly sow-thistle is a complex and interesting plant species that has both positive and negative impacts. While it has been used for food and medicine in some cultures, it can also be an invasive species that can negatively impact the local ecosystem. Understanding the characteristics of this plant and its ecological impacts can help individuals to effectively control its spread and protect native species from its negative impacts. By implementing effective control measures and promoting the growth of native plant species, we can help to limit the spread of prickly sow-thistle and protect the diversity and stability of our local ecosystems.

More Uses

The prickly sow-thistle has a long history of use in traditional medicine. It has been used to treat a range of ailments, including liver disorders, digestive issues, and skin conditions. Some studies have suggested that the plant has anti-inflammatory and antioxidant properties, which may contribute to its medicinal benefits. The prickly sow-thistle has also been used as a diuretic, helping to increase urine production and eliminate excess fluids from the body.

In addition to its medicinal uses, the prickly sow-thistle has been used as a food source in some cultures. The leaves of the plant can be eaten raw in salads or cooked as a vegetable. The plant has a slightly bitter taste, which can be reduced by boiling the leaves in water for several minutes. The prickly sow-thistle can also be used as a fodder crop for livestock, providing a source of nutrition during the growing season.

Cultural Significance

The prickly sow-thistle has played a role in many cultures throughout history. In ancient Greece, the plant was associated with the god Apollo and was believed to have healing properties. In traditional Chinese medicine, the prickly sow-thistle has been used to treat a range of conditions, including liver disease, arthritis, and high blood pressure. The plant has also been used in traditional African medicine to treat coughs, colds, and fevers.

In some cultures, the prickly sow-thistle is also associated with folklore and superstition. In parts of Europe, the plant was believed to have magical properties and was used to ward off evil spirits. In other regions, the plant was believed to bring good luck and prosperity.


The prickly sow-thistle is a fascinating plant species with a long history of use in traditional medicine and as a food source. While it can be an invasive species in some areas, its adaptability and hardiness have also made it a valuable resource in many cultures. Understanding the different uses and cultural significance of the prickly sow-thistle can help us to appreciate its complexity and diversity, and to find ways to manage its ecological impacts while preserving its cultural heritage. By working together to balance the benefits and risks of this plant species, we can ensure a sustainable and healthy future for our communities and our planet.


Prickly Sow-thistle filmed by the side of the Leeds and Liverpool Canal, Lancashire on the 7th July 2022.


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Distribution Map

Reproduced by kind permission of the BSBI.

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