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Common Knotgrass

Polygonum aviculare

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.

Plant Profile
Similar Species
Other Information
Distribution Map

Flowering Months:

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Order:

Caryophyllales

Family:

Polygonaceae (Dock)

Also in this family:

Alpine Bistort, Amphibious Bistort, Argentine Dock, Black Bindweed, Broad-leaved Dock, Clustered Dock, Common Bistort, Common Buckwheat, Common Sorrel, Copse Bindweed, Cornfield Knotgrass, Curled Dock, Equal-leaved Knotgrass, Fiddle Dock, French Sorrel, Garden Rhubarb, Giant Knotweed, Golden Dock, Greek Dock, Himalayan Knotweed, Iceland Purslane, Japanese Knotweed, Least Water-pepper, Lesser Knotweed, Marsh Dock, Monk's Rhubarb, Mountain Sorrel, Northern Dock, Northern Knotgrass, Pale Persicaria, Patience Dock, Pink Knotweed, Ray's Knotgrass, Red Bistort, Redleg, Russian Vine, Scottish Dock, Sea Knotgrass, Sheep Sorrel, Shore Dock, Tasteless Water-pepper, Water Dock, Water-pepper, Wood Dock

Type:

Flower

Life Cycle:

Annual

Maximum Size:

50 centimetres tall

Habitats:

Fields, gardens, grassland, lawns, meadows, mud, roadsides, sand dunes, towns, wasteland.

Flower:

Variable in colour, 5 petals

The flowers of Common Knotgrass typically possess small, inconspicuous greenish blooms that adorn the plant from spring through autumn. These flowers, although modest in appearance, hold a subtle charm with their delicate structure and muted hue. Nestled amidst the slender stems and elongated green leaves, the flowers add a touch of understated elegance to the plant's overall demeanor. Despite their diminutive size, they contribute to the plant's reproductive cycle, facilitating the production of seeds that aid in its widespread dispersal. While not as showy as those of some garden varieties, the flowers of Common Knotgrass possess a quiet beauty that harmonizes with its natural surroundings, embodying the resilience and adaptability of this ubiquitous species in the British landscape.

Fruit:

The fruit of Common Knotgrass is characterized by its small and inconspicuous nature, mirroring the unassuming demeanor of the plant itself. These fruits, often referred to as achenes, develop following the flowering period and are typically greenish-brown or dark brown in colour. Each achene is encapsulated within the remnants of the flower, forming a tiny, hardened shell that protects the seed within. Despite their diminutive size, the fruits play a crucial role in the plant's reproductive process, serving as vessels for the dispersal of seeds. As the plant matures, these fruits gradually ripen, eventually releasing their seeds into the surrounding environment. This modest yet essential aspect of Common Knotgrass' life cycle contributes to its ability to colonize a diverse range of habitats throughout the United Kingdom, underscoring its status as a resilient and adaptable species in the British flora.

Leaves:

The leaves of Common Knotgrass exhibit a distinctively slender and elongated shape, tapering to a point at each end. Typically green in colour, these leaves are characterized by their smooth texture and lack of prominent veining. Arranged alternately along the stems, they form dense mats of foliage, particularly in areas where the plant thrives abundantly. Despite their unassuming appearance, the leaves of Common Knotgrass play a vital role in the plant's survival and growth, serving as the primary site for photosynthesis and nutrient absorption. Their resilient nature allows them to withstand various environmental conditions, including drought and poor soil quality, contributing to the plant's ability to colonize a wide range of habitats across the United Kingdom.

Aroma:

Common Knotgrass typically does not possess a distinctive scent. The plant's foliage and flowers are generally odourless, contributing to its unobtrusive presence in the natural environment. While some individuals may detect a faint, earthy aroma when handling the leaves or crushing the plant, it is usually minimal and not considered significant. Common Knotgrass is valued more for its resilience and adaptability in various habitats rather than for any olfactory characteristics. In gardens or outdoor spaces where it may be present, the scent of Common Knotgrass is unlikely to be a noticeable feature, allowing its visual qualities to take precedence in the appreciation of this ubiquitous plant in the United Kingdom.

Other Names:

Bird Grass, Birdweed, Doorweed, Iron Grass, Low Grass, Mat Grass, Pigweed, Prostrate Knotweed, Stone Grass.

Frequency (UK):

Common

Equal-leaved Knotgrass

Northern Knotgrass

Summary

Polygonum aviculare, also known as common knotgrass or prostrate knotweed, is a species of flowering plant in the Polygonaceae family. It is native to Europe, Asia and North Africa, and can be found in a variety of habitats, including gardens, roadsides, and waste ground. It is a low-growing, mat-forming perennial herb that can spread aggressively and is considered an invasive species in many areas. The leaves are narrow and pointed, and the small pink or white flowers appear in summer. It has been used for medicinal purposes for a variety of ailments like wound healing, skin diseases and burns.

Blog

Polygonum aviculare, commonly known as Common Knotgrass, is a ubiquitous plant that belongs to the family Polygonaceae. This plant is found almost all over the world, including Europe, Asia, Africa, North America, and Australia. The Common Knotgrass is a low-growing annual plant that can grow up to 50 cm in height. It is a hardy and resilient plant that can grow in a variety of habitats, including lawns, gardens, fields, and wastelands.

The leaves of the Common Knotgrass are narrow and lance-shaped, with a smooth surface and a pointed tip. The plant's stem is slender and often reddish, with nodes that give rise to small, inconspicuous flowers. The flowers of the Common Knotgrass are pale pink or white and are arranged in clusters at the tips of the stems. The plant blooms from June to September.

The Common Knotgrass has a long history of use in traditional medicine. It is believed to have astringent and diuretic properties and has been used to treat a variety of ailments, including diarrhea, dysentery, and urinary tract infections. The plant contains several biologically active compounds, including flavonoids, tannins, and phenolic acids, which may contribute to its medicinal properties.

In addition to its medicinal uses, the Common Knotgrass has also been used as a food source. The young leaves and shoots of the plant are edible and can be eaten raw or cooked. The plant's seeds are also edible and can be ground into a flour or used as a coffee substitute.

Despite its usefulness, the Common Knotgrass is often considered a weed due to its ability to spread quickly and grow in a variety of environments. The plant is particularly problematic in agricultural fields, where it can compete with crops for nutrients and water. However, the Common Knotgrass is also an important food source for many birds and small mammals, and its presence can contribute to the biodiversity of an ecosystem.

Facts about Common Knotgrass

Common Knotgrass is a versatile plant that has a wide range of uses and benefits. Here are some additional facts and information about this fascinating plant:

Common Knotgrass is also known by several other common names, including birdweed, pigweed, and prostrate knotweed.
The plant's scientific name, Polygonum aviculare, is derived from the Greek words "poly" meaning many and "gonu" meaning knee, referring to the plant's many-jointed stem.
The leaves of the Common Knotgrass are rich in vitamin C, and they were traditionally used to treat scurvy, a disease caused by a deficiency of this vitamin.
The plant's roots contain a substance called emodin, which has been found to have anti-inflammatory and anti-cancer properties.
Common Knotgrass has been used in traditional Chinese medicine for centuries to treat a variety of conditions, including skin disorders, hemorrhoids, and menstrual problems.
The plant has also been used in Ayurvedic medicine to treat digestive disorders, respiratory problems, and skin conditions.
In addition to its medicinal and culinary uses, Common Knotgrass has been used for a variety of other purposes. For example, the plant's tough stems have been used to make baskets and ropes.
Common Knotgrass is often used as a ground cover in gardens and landscapes, as it can help to prevent soil erosion and suppress weed growth.
The plant's ability to absorb heavy metals from the soil has also made it useful for phytoremediation, a process in which plants are used to clean up contaminated soil.
Despite its many uses and benefits, Common Knotgrass can be invasive in certain environments and may require management to prevent it from spreading too aggressively.

Overall, Common Knotgrass is a fascinating plant with a rich history and many potential uses. Whether you are interested in its medicinal properties, culinary potential, or environmental benefits, there is much to learn and appreciate about this versatile plant.

Blog continued...

Polygonum aviculare, commonly known as Common Knotgrass, is a ubiquitous plant that has many uses and benefits. It is a low-growing annual plant that can grow up to 50 cm in height and is found almost all over the world, including Europe, Asia, Africa, North America, and Australia. The leaves of the Common Knotgrass are narrow and lance-shaped, with a smooth surface and a pointed tip. The plant's stem is slender and often reddish, with nodes that give rise to small, inconspicuous flowers. The flowers of the Common Knotgrass are pale pink or white and are arranged in clusters at the tips of the stems. The plant blooms from June to September.

Common Knotgrass has a long history of use in traditional medicine. It is believed to have astringent and diuretic properties and has been used to treat a variety of ailments, including diarrhea, dysentery, and urinary tract infections. The plant contains several biologically active compounds, including flavonoids, tannins, and phenolic acids, which may contribute to its medicinal properties. The plant's roots contain a substance called emodin, which has been found to have anti-inflammatory and anti-cancer properties.

In addition to its medicinal uses, Common Knotgrass has also been used as a food source. The young leaves and shoots of the plant are edible and can be eaten raw or cooked. The plant's seeds are also edible and can be ground into a flour or used as a coffee substitute.

Common Knotgrass has been used for a variety of other purposes as well. For example, the plant's tough stems have been used to make baskets and ropes. Common Knotgrass is often used as a ground cover in gardens and landscapes, as it can help to prevent soil erosion and suppress weed growth. The plant's ability to absorb heavy metals from the soil has also made it useful for phytoremediation, a process in which plants are used to clean up contaminated soil.

Common Knotgrass is a versatile plant with many uses and benefits. Its medicinal properties, culinary potential, and environmental benefits make it an important plant to study and understand. While it can be invasive in certain environments, its ability to thrive in a variety of habitats and provide food and habitat for wildlife makes it an interesting and valuable plant to many.

More Information about Common Knotgrass

Polygonum aviculare: A Versatile Plant with Many Uses and Benefits

Polygonum aviculare, commonly known as Common Knotgrass, is a plant that has many uses and benefits. It is a low-growing annual plant found almost all over the world, with a long history of use in traditional medicine, as well as culinary and environmental applications.

Medicinal Uses

Common Knotgrass has astringent and diuretic properties, and has been used to treat a variety of ailments, including diarrhea, dysentery, and urinary tract infections. The plant contains several biologically active compounds, including flavonoids, tannins, and phenolic acids, which may contribute to its medicinal properties. The plant's roots contain emodin, which has anti-inflammatory and anti-cancer properties.

Culinary Uses

The young leaves and shoots of the Common Knotgrass are edible and can be eaten raw or cooked. The plant's seeds are also edible and can be ground into a flour or used as a coffee substitute.

Environmental Uses

Common Knotgrass is often considered a weed due to its ability to spread quickly and grow in a variety of environments. However, the plant is an important food source for many birds and small mammals, and its presence can contribute to the biodiversity of an ecosystem. The plant is often used as a ground cover in gardens and landscapes, as it can help to prevent soil erosion and suppress weed growth. Additionally, the plant's ability to absorb heavy metals from the soil has made it useful for phytoremediation, a process in which plants are used to clean up contaminated soil.

Conclusion

Common Knotgrass is a versatile plant that has been used for centuries for its medicinal and culinary properties, as well as its environmental benefits. While it can be invasive in certain environments, its ability to thrive in a variety of habitats and provide food and habitat for wildlife makes it an interesting and valuable plant to many. Further research on the plant's biologically active compounds and their potential uses could reveal even more benefits and applications for this fascinating plant.

15 Common Knotgrass Facts

Here are 15 facts about Common Knotgrass:

Common Knotgrass, scientifically known as Polygonum aviculare, is a widespread flowering plant found in various habitats around the world.
It belongs to the family Polygonaceae and is often considered a weed in gardens and agricultural fields.
Despite its status as a weed, Common Knotgrass has been used traditionally in herbal medicine for its purported medicinal properties.
The plant typically grows low to the ground, with slender stems and small green leaves that are shaped like elongated ovals.
Common Knotgrass produces small, inconspicuous greenish flowers that bloom from spring to autumn.
It is commonly found in disturbed areas, such as roadsides, fields, and gardens, thriving in a variety of soil types.
The plant is highly adaptable and can tolerate a wide range of environmental conditions, including poor soil quality and drought.
Common Knotgrass is known for its ability to spread rapidly, thanks to its prolific seed production and its ability to root at nodes along its stems.
Despite its aggressive growth habit, Common Knotgrass can provide erosion control and stabilize soil in certain situations.
The seeds of Common Knotgrass are edible and have been used as a food source in some cultures, although they are small and not particularly flavorful.
In traditional medicine, Common Knotgrass has been used to treat various ailments, including inflammation, gastrointestinal issues, and skin conditions.
Some studies suggest that extracts from Common Knotgrass may possess antioxidant and anti-inflammatory properties, though more research is needed to confirm its efficacy.
The plant is also known by various common names, including prostrate knotweed, wiregrass, and birdweed.
Common Knotgrass is often considered a nuisance in lawns and gardens due to its ability to outcompete desirable plants and form dense mats of vegetation.
Despite its reputation as a weed, Common Knotgrass can be appreciated for its resilience and adaptability to diverse environments.

Videos

Video 1: Common Knotgrass filmed in the sand dunes of Formby, Lancashire on the 25th September 2022.

Video 2: Common Knotgrass filmed at Little Rissington in Gloucestershire on the 26th June 2023.

Video 3: Common Knotgrass filmed around various locations in Lancashire throughout July 2023.

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Reproduced by kind permission of the BSBI.

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