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Plymouth Thistle

Carduus pycnocephalus

Please keep in mind that it is illegal to uproot a plant without the landowner's consent and care should be taken at all times not to damage wild plants. Wild plants should never be picked for pleasure and some plants are protected by law.
For more information please download the BSBI Code of Conduct PDF document.

Contents

Plant Profile

Flowering Months:
JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
Order:
Asterales
Family:
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, Pontic Blue Sow-thistle, Pot Marigold, Prickly Lettuce, Prickly Sow-thistle, 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, Trifid Bur-marigold, Tuberous Thistle, Tyneside Leopardplant, Viper's Grass, Wall Lettuce, Welsh Groundsel, Welted Thistle, 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
Type:
Flower
Life Cycle:
Annual
Maximum Size:
150 centimetres tall
Habitats:
Cliffs, fields, roadsides, sea cliffs, seaside, wasteland.

Flower:
֍
Purple, many petals
 
Pinkish-purple flowers with hairy bracts. The flowers are either solitary or appear in clusters of 2 to 5 (but sometimes more than 5).
Fruit:
Bristly, golden brown fruits with minute hooks.
Leaves:
A annual or biennial flower with deeply cut leaves. The leaves each have between 2 and 5 pairs of lobes. The undersides of the leaves are slightly woolly. The leaves measure anything up to 6 inches (15cm) in diameter. The stems are spiny winged. The stems are not as spiny as those of the similar looking Slender Thistle (Carduus tenuiflorus).
Other Names:
Compact-headed Thistle, Italian Plumeless Thistle, Italian Thistle, Shore Thistle.
Frequency (UK):
Rarely seen  

Similar Species

Other Information

Summary

Carduus pycnocephalus, also known as the Italian thistle, is a species of thistle that is native to the Mediterranean region. It is a biennial plant that can grow up to 1.5 meters tall. The leaves are spiny and the flower heads are purple or pink. It is considered an invasive weed in many parts of the world, particularly in Australia and New Zealand.

Blog

Plymouth Thistle: A Unique and Invasive Species

Plymouth Thistle, also known as Carduus pycnocephalus, is a species of thistle that is native to the Mediterranean region but has now become an invasive species in many parts of the world, including the United States and Europe. This plant is known for its distinctive appearance, with its prickly leaves and large, purple flower heads.

One of the reasons why Plymouth Thistle has become so successful in its invasive range is due to its ability to adapt to a variety of habitats. It can be found in meadows, grasslands, roadsides, and even in waste areas. This adaptability, combined with its ability to spread quickly, has made it a difficult plant to control once established in an area.

The Plymouth Thistle is also known for its prickly leaves, which are covered in small, sharp spines that can cause skin irritation and make it difficult for other plants to grow near it. This has earned it a reputation as a nuisance plant and has led to efforts to control its spread.

Despite its negative impact on native habitats, Plymouth Thistle is still appreciated for its unique appearance. The large, purple flower heads of the plant are a striking sight, especially in the summer months when they are in full bloom. In addition, its dense growth habit provides a valuable source of habitat for many different species of insects, including bees and butterflies.

If you come across Plymouth Thistle in your area, it is important to take action to prevent its spread. This can be done by removing it before it goes to seed and disposing of the plant material in a way that will prevent it from spreading to new areas. Additionally, it is important to be cautious when working near the plant, as its spines can cause skin irritation.

Plymouth Thistle is a unique and invasive species that has gained a reputation as a nuisance plant due to its ability to adapt to a variety of habitats and its prickly leaves. Despite its negative impact on native habitats, it is still appreciated for its unique appearance and provides a valuable source of habitat for many different species of insects. If you come across Plymouth Thistle in your area, it is important to take action to prevent its spread.

The Plymouth Thistle has also been used for medicinal purposes in traditional medicine for centuries. Its leaves and stems have been used to treat a variety of conditions, including digestive problems, respiratory infections, and skin irritation. However, it is important to note that due to its prickly leaves and the risk of skin irritation, it is best to use caution when handling the plant and to consult with a medical professional before using it for medicinal purposes.

In addition to its medicinal uses, the Plymouth Thistle has also been used for ornamental purposes. Its large, purple flower heads and distinctive appearance make it a popular choice for gardeners who are looking for a unique and eye-catching plant. However, it is important to be cautious when using this plant in a garden, as it can easily spread and become a nuisance.

In addition to its spread in the United States and Europe, Plymouth Thistle has also been introduced to Australia, where it has become a significant problem for native habitats and wildlife. In order to combat this invasive species, many countries have implemented control measures, including the use of chemical and biological control methods.

One of the most effective biological control methods is the introduction of natural predators, such as the Cinnabar Moth, which feeds on the leaves and stems of the Plymouth Thistle. This method has been successful in reducing the spread of the plant in some areas, and is considered a more environmentally friendly alternative to chemical control methods.

However, despite the efforts to control the spread of Plymouth Thistle, it remains a challenge due to its adaptability and ability to spread quickly. As such, it is important to continue monitoring and managing this species in order to prevent further harm to native habitats and wildlife.

In conclusion, Plymouth Thistle is a unique and invasive species that has become a problem in many parts of the world due to its adaptability and ability to spread quickly. Despite the efforts to control its spread, it remains a challenge, and it is important to continue monitoring and managing this species in order to prevent further harm to native habitats and wildlife. If you encounter Plymouth Thistle in your area, it is important to take action to prevent its spread and to be cautious when handling the plant, as its spines can cause skin irritation.


Distribution Map

Reproduced by kind permission of the BSBI.

Click to open an Interactive Map