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Persicaria hydropiper

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Plant Profile

Flowering Months:
Polygonaceae (Dock)
Life Cycle:
Maximum Size:
75 centimetres tall
Bogs, ditches, fields, floodplains, gardens, grassland, lawns, marshes, meadows, ponds, riverbanks, roadsides, seaside, wasteland, waterside, wetland, woodland.

Green, 5 petals
Greenish-pink or pinkish-white nodding, slender flower spikes. The flowers are covered in yellow glands. Shortly fringed sheaths, or no sheaths at all. The 5 petals are actually sepals.
Water-pepper is a herbaceous plant with slender, pointed leaves and small, delicate flowers. The fruit of water-pepper is a small, three-sided nutlet. These nutlets are typically produced in clusters and contain seeds. The plant is known for its pungent and peppery taste, lending its name to the "water-pepper" moniker. While not commonly consumed as a fruit in the traditional sense, it is valued for its culinary uses and medicinal properties.
An annual flower with thin, narrow leaves tapering into a short stalk. The leaves are not blotched as with some other Persicaria species. Alternate leaves with entire margins. Short-stalked and not hairy.
Water-pepper is known for its distinctive and pungent aroma. The plant exudes a peppery scent, which is reminiscent of black pepper. The aroma is generally robust and spicy, reflecting the plant's reputation for its intense and sharp flavour. While not as commonly used for its fragrance as it is for its culinary or medicinal properties, the aroma of water-pepper can contribute to the overall sensory experience when used in cooking or as a seasoning. It is advisable to use water-pepper sparingly due to its potent aroma and flavour.
Other Names:
Bite-tongue, Ciderage, Culrage, Curage, Lakeweed, Marshpepper Knotweed, Red Knees, Red Leaves, Smartweed, Water Pepperwort.
Frequency (UK):

Similar Species

Other Information


Persicaria hydropiper, commonly known as water pepper, marshpepper knotweed, arse smart or tade, is a plant of the family Polygonaceae. It is a widespread species, found in Europe, North and South America, Asia and Africa. It has wavy leaves that resemble those of the native Swamp Smartweed (Persicaria amphibia) and a pepper-like flavor in all parts of the plant. The plant is used in traditional medicine and has been found to contain flavonoids and terpenoids, as well as insect deterrents, which may account for its traditional use as a pesticide. It has also been found to activate the Wnt/β-catenin pathway and inhibit adipocyte differentiation, suggesting potential applications in obesity and related diseases.


Water-pepper, also known as Persicaria hydropiper, is a versatile and highly sought-after herb that has been used for medicinal and culinary purposes for centuries. This aquatic plant is a member of the Polygonaceae family and is found in wet and marshy areas throughout much of the world.

One of the key features of water-pepper is its pungent, peppery flavor. This makes it a popular ingredient in traditional dishes, sauces, and condiments. It is often used as a substitute for black pepper, as its flavor is similar, but slightly milder. This herb can be dried, ground, and used as a spice in many recipes, or it can be added fresh to salads, soups, and stews.

In addition to its culinary uses, water-pepper has also been used for medicinal purposes. It is believed to have anti-inflammatory, antioxidant, and anti-bacterial properties. Traditional healers have used it to treat a variety of ailments, including digestive problems, skin conditions, and fever.

Water-pepper can be easily grown in wet soil and can thrive in sunny or partially shaded areas. It prefers moist soil, so it is best to water it regularly and keep it in an area that does not experience prolonged drought. When growing water-pepper, it is important to keep it from spreading too much, as it can quickly take over a garden.

In conclusion, water-pepper is a versatile and flavorful herb that has a long history of use in both cooking and medicine. Its pungent, peppery flavor makes it a popular ingredient in a variety of dishes, and its medicinal properties make it a valuable addition to any herb garden. Whether you are a seasoned gardener or a beginner, water-pepper is a plant worth considering for your next garden project.

Water-pepper is also known for its unique appearance. It has green, arrow-shaped leaves that grow in a cluster and can reach up to 15 cm in length. The leaves are surrounded by delicate white or pink flowers that bloom from June to September. The plant itself can grow up to 60 cm tall, making it a great addition to any wetland or pond area.

Another important aspect of water-pepper is its ecological significance. This plant is an important food source for a variety of wildlife, including birds, insects, and other aquatic species. It is also a great plant for improving water quality and providing habitat for aquatic wildlife.

In some parts of the world, water-pepper is considered an invasive species. This is because it can spread quickly and outcompete native plants. If you are growing water-pepper in an area where it is not native, it is important to keep it contained and not let it spread into natural areas.

In recent years, water-pepper has received increased attention for its potential use in phytoremediation, which is the use of plants to remove pollutants from the environment. Studies have shown that water-pepper has the ability to remove heavy metals and other pollutants from contaminated water, making it a valuable tool for environmental restoration efforts.

Water-pepper is a versatile and valuable herb that has a wide range of uses and benefits. Whether you are looking to add flavor to your cooking, improve water quality, or provide habitat for wildlife, water-pepper is a plant worth considering.

In addition to its culinary and medicinal uses, water-pepper has also been used in traditional herbal remedies for various ailments. In folklore medicine, it has been used to treat wounds, cuts, and burns. The juice from the leaves and stems of the plant is believed to have antiseptic properties that can help to prevent infection and promote healing.

Water-pepper is also thought to have analgesic and anti-inflammatory properties, making it a useful herb for the treatment of pain and swelling. It is believed to have the ability to reduce inflammation in the body and alleviate pain, making it a popular ingredient in topical creams and ointments.

One of the most interesting aspects of water-pepper is its role in traditional folklore. In some cultures, it is believed to have magical properties and is used in rituals and spells. For example, it is sometimes used in love spells and to ward off evil spirits.

Aside from its traditional uses, water-pepper is also an important plant for research and scientific study. It is a source of many bioactive compounds, including flavonoids, tannins, and alkaloids, that are being studied for their potential health benefits. The plant is also being studied for its ability to absorb heavy metals from contaminated water, which has important implications for environmental sustainability.

In conclusion, water-pepper is a versatile and valuable plant that has a wide range of uses and benefits. Whether you are using it for culinary, medicinal, or environmental purposes, this herb is a great addition to any garden or kitchen.

30 Water-pepper Facts

  1. Scientific Name: Water-pepper is scientifically known as Persicaria hydropiper.

  2. Habitat: It is commonly found in damp or wet habitats, such as riverbanks, marshes, and wet meadows.

  3. Appearance: The plant has slender stems, pointed leaves, and small, pink or white flowers arranged in dense spikes.

  4. Edibility: While edible, water-pepper is primarily used as a seasoning due to its strong and peppery taste.

  5. Peppery Taste: Water-pepper has a distinct peppery flavour, akin to black pepper, which can be overwhelming if used excessively.

  6. Culinary Use: It is used sparingly in salads, soups, and as a seasoning to add a peppery kick to dishes.

  7. Traditional Medicine: Water-pepper has been used in traditional medicine for its potential medicinal properties.

  8. Nutlets: The fruit of water-pepper consists of small, three-sided nutlets produced in clusters.

  9. Spreading Habit: The plant can have a spreading or prostrate growth habit, forming dense colonies in suitable habitats.

  10. Height: It typically grows to a height of around 30 to 90 centimetres.

  11. Adaptability: Water-pepper is adaptable to a range of soil types but prefers moist conditions.

  12. Season: It blooms from late spring to early autumn, producing spikes of flowers during this period.

  13. Invasive Species: In some regions, water-pepper can be considered invasive due to its ability to form dense colonies and outcompete native vegetation.

  14. Wildlife Habitat: The plant provides habitat and food for various insects and birds.

  15. Aromatic Properties: Water-pepper has a strong and distinctive aroma, contributing to its culinary appeal.

  16. Hardiness: It is a hardy plant, capable of withstanding various environmental conditions.

  17. Allelopathic Effects: Water-pepper has allelopathic effects, inhibiting the growth of certain competing plants.

  18. Perennial: Water-pepper is a perennial plant, returning year after year.

  19. Cultural Significance: In some cultures, water-pepper has historical or cultural significance, often tied to traditional medicinal uses.

  20. Propagation: The plant can reproduce through both seeds and rhizomes, contributing to its ability to colonize areas.

  21. Diversity: There are several varieties of water-pepper with subtle differences in appearance and habitat preferences.

  22. Water Conservation: Its preference for damp environments makes water-pepper valuable in water conservation efforts in certain ecosystems.

  23. Botanical Family: Water-pepper belongs to the Polygonaceae family.

  24. Attracts Pollinators: The flowers attract pollinators such as bees, butterflies, and hoverflies.

  25. Drought Tolerance: While it prefers moist conditions, water-pepper can exhibit some degree of drought tolerance.

  26. Inhibitory Chemicals: The plant produces chemicals that inhibit the growth of nearby plants, contributing to its competitive advantage.

  27. Folk Names: Water-pepper is also known by various folk names, including smartweed and water smartweed.

  28. Herbal Infusions: The leaves of water-pepper can be used to make herbal infusions with potential health benefits.

  29. Ethnobotanical Uses: Different cultures may have diverse ethnobotanical uses for water-pepper, ranging from culinary applications to medicinal remedies.

  30. Conservation Concerns: In some regions, the aggressive growth of water-pepper raises conservation concerns, particularly in native plant communities.


Water-pepper filmed around the Chorley region of Lancashire on the 21st July 2023 and 20th August 2023.


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Distribution Map

Reproduced by kind permission of the BSBI.

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