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Knotweeds (Polygonum)
The knotweeds (Polygonum) are a sizable and diverse group of mostly temperate flowering plants. Several species within this genus have historically been eaten by humans, although few have been widely cultivated as food sources. One exception to this is Madimak (P. cognatum), which is quite popular as a green in Turkish cuisine, and is today heavily cultivated in the central part of that country. Being hardy, colonizing species that spread quickly, several knotweeds are also considered pesky invasives beyond their native ranges.
Lifespan
Perennial
Key Facts About Knotweeds
Feedback
Attributes of Knotweeds
Leaf type
Semi-evergreen
Trivia and Interesting Facts
This plant was found in Philadelphia around 1910. It is a kind of rice field weed that is hard to remove because of its strong viability in wetlands, river banks, grasslands, moors and mudflats.
Scientific Classification of Knotweeds
Phylum
Vascular plants
Class
Dicotyledons
Order
Pinks, cacti, and allies
Family
Buckwheat
Genus
Knotweeds
Distribution of Knotweeds
Feedback
Distribution Map of Knotweeds
Native
Cultivated
Invasive
Potentially invasive
Exotic
No species reported
How to Grow and Care for Knotweeds
Feedback
Knotweeds comprises versatile plants with varying care needs. They typically prefer full sun to partial shade, consistent moisture without waterlogging, and thrive in well-draining soils. Gardeners may encounter challenges from pests like aphids and diseases such as powdery mildew. Seasonal care involves mulching for winter protection, pruning in late winter or early spring, and increased watering during hot summers, with reduced frequency in cooler months.
Exploring the Knotweeds Plants
Feedback
8 most common species：
Prostrate knotweed
Prostrate knotweed (Polygonum aviculare) is a low-growing species that can root practically anywhere. It produces many small white flowers each summer and produces plenty of seeds that can survive for years. Its seeds can lay dormant in soils, and once they see sunlight, they will start to germinate. Because it grows so dwarf, mowing is not effective in removing it.
Oval leaf knotweed
Oval leaf knotweed (Polygonum arenastrum) is an invasive plant native to Europe that can now be found throughout North America as well. It sends out a long tap root that helps make it very drought-tolerant. Oval leaf knotweed prefers dense, compacted soils. Though a bane of large-scale farmers, it can usually be pulled by hand in smaller gardens.
Sawatch knotweed
Sawatch knotweed (Polygonum sawatchense) is an annual herb in the buckwheat family that is found throughout western North America. Like other flowering plants in the Polygonum family, this knotweed is known to attract the Purplish Copper Butterfly.
Sea knotgrass
Sea knotgrass is a perennial plant that can be found growing on sand and shingle beaches. The Latin name, Polygonum maritimum, translates to "many joints" (polygonum) and "seashore" (maritimum). These refer to sea knotgrass's thick, woody stems, which the plant is renowned for, as well as the coastal areas it inhabits.
Seaside knotweed
Seaside knotweed is a hardy coastal plant favoring sandy shores and dunes. Known for its bluish-gray, waxy foliage, seaside knotweed is adapted to withstand salty sprays and dry conditions. This low-growing perennial herb has small, inconspicuous flowers and often forms sprawling mats, providing stabilization to its sandy habitat.
Beach knotweed
Polygonum paronychia is a small prostrate or upright shrub producing multibranched brown stems up to a meter long. The leaves are linear to lance-shaped with rolled edges and bristly midribs on the undersides. Flowers occur in the leaf axils, with five narrow white or pinkish corolla lobes.
Ray's knotgrass
Ray's knotgrass is a hardy coastal herbaceous plant known for its ability to thrive in sandy and saline soils. It possesses a sprawling habit with reddish stems that can either climb or spread across the ground. The leaves of ray's knotgrass are narrow and taper to a pointed tip, while it bears small, inconspicuous white flowers which develop into sharply angular seeds, a characteristic feature for the species. Adapted to high stress environments, ray's knotgrass often takes root in disturbed habitats and can endure harsh coastal weather.
Shasta knotweed
Shasta knotweed is a hardy alpine plant with a tufted growth habit, flourishing in the rocky soils of mountainous terrains. Its stems are slender, supporting teardrop-shaped leaves and clusters of tiny, pale pink flowers that bloom in the warmth of late spring to summer. The plant's compact form is an adaptation to withstand the harsh, windy conditions at high elevations.
All Species of Knotweeds
Prostrate knotweed
Prostrate knotweed
Prostrate knotweed (Polygonum aviculare) is a low-growing species that can root practically anywhere. It produces many small white flowers each summer and produces plenty of seeds that can survive for years. Its seeds can lay dormant in soils, and once they see sunlight, they will start to germinate. Because it grows so dwarf, mowing is not effective in removing it.
Oval leaf knotweed
Oval leaf knotweed
Oval leaf knotweed (Polygonum arenastrum) is an invasive plant native to Europe that can now be found throughout North America as well. It sends out a long tap root that helps make it very drought-tolerant. Oval leaf knotweed prefers dense, compacted soils. Though a bane of large-scale farmers, it can usually be pulled by hand in smaller gardens.
Sawatch knotweed
Sawatch knotweed
Sawatch knotweed (Polygonum sawatchense) is an annual herb in the buckwheat family that is found throughout western North America. Like other flowering plants in the Polygonum family, this knotweed is known to attract the Purplish Copper Butterfly.
Sea knotgrass
Sea knotgrass
Sea knotgrass is a perennial plant that can be found growing on sand and shingle beaches. The Latin name, Polygonum maritimum, translates to "many joints" (polygonum) and "seashore" (maritimum). These refer to sea knotgrass's thick, woody stems, which the plant is renowned for, as well as the coastal areas it inhabits.
Seaside knotweed
Seaside knotweed
Seaside knotweed is a hardy coastal plant favoring sandy shores and dunes. Known for its bluish-gray, waxy foliage, seaside knotweed is adapted to withstand salty sprays and dry conditions. This low-growing perennial herb has small, inconspicuous flowers and often forms sprawling mats, providing stabilization to its sandy habitat.
Beach knotweed
Beach knotweed
Polygonum paronychia is a small prostrate or upright shrub producing multibranched brown stems up to a meter long. The leaves are linear to lance-shaped with rolled edges and bristly midribs on the undersides. Flowers occur in the leaf axils, with five narrow white or pinkish corolla lobes.
Ray's knotgrass
Ray's knotgrass
Ray's knotgrass is a hardy coastal herbaceous plant known for its ability to thrive in sandy and saline soils. It possesses a sprawling habit with reddish stems that can either climb or spread across the ground. The leaves of ray's knotgrass are narrow and taper to a pointed tip, while it bears small, inconspicuous white flowers which develop into sharply angular seeds, a characteristic feature for the species. Adapted to high stress environments, ray's knotgrass often takes root in disturbed habitats and can endure harsh coastal weather.
Shasta knotweed
Shasta knotweed
Shasta knotweed is a hardy alpine plant with a tufted growth habit, flourishing in the rocky soils of mountainous terrains. Its stems are slender, supporting teardrop-shaped leaves and clusters of tiny, pale pink flowers that bloom in the warmth of late spring to summer. The plant's compact form is an adaptation to withstand the harsh, windy conditions at high elevations.
Milkwort knotweed
Milkwort knotweed
Milkwort knotweed is a small, herbaceous perennial with wiry stems and narrow leaves. It adapts to various moist habitats, often found near water sources. Blossoming in summer, milkwort knotweed features tiny pink or white flowers in dense clusters. Its ability to thrive in wet conditions makes it an important stabilizer in fragile ecosystems.
More Popular Genus
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Dracaena
Dracaena are popular house plants that are easy to grow. They can tolerate low-light conditions and require little watering. Their leaves range from variegated to dark green. Their characteristic traits include woody stems that grow slowly but offer a striking appearance for small spaces such as apartments or offices.
Fig trees
Fig trees have been cultivated in many regions for their fruits, particularly the common fig, F. carica. Most of the species have edible fruits, although the common fig is the only one of commercial value. Fig trees are also important food sources for wildlife in the tropics, including monkeys, bats, and insects.
Brambles
Brambles are members of the rose family, and there are hundreds of different types to be found throughout the European countryside. They have been culturally significant for centuries; Christian folklore stories hold that when the devil was thrown from heaven, he landed on a bramble bush. Their vigorous growth habit can tangle into native plants and take over.
Maples
The popular tree family known as maples change the color of their leaves in the fall. Many cultural traditions encourage people to watch the colors change, such as momijigari in Japan. Maples popular options for bonsai art. Alternately, their sap is used to create maple syrup.
Prunus
Prunus is a genus of flowering fruit trees that includes almonds, cherries, plums, peaches, nectarines, and apricots. These are often known as "stone fruits" because their pits are large seeds or "stones." When prunus trees are damaged, they exhibit "gummosis," a condition in which the tree's gum (similar to sap) is secreted to the bark to help heal external wounds.
Nightshades
Nightshades is a large and diverse genus of plants, with more than 1500 different types worldwide. This genus incorporates both important staple food crops like tomato, potato, and eggplant, but also dangerous poisonous plants from the nightshade family. The name was coined by Pliny the Elder almost two thousand years ago.
Roses
Most species of roses are shrubs or climbing plants that have showy flowers and sharp thorns. They are commonly cultivated for cut flowers or as ornamental plants in gardens due to their attractive appearance, pleasant fragrance, and cultural significance in many countries. The rose hips (fruits) can also be used in jams and teas.
Oaks
Oaks are among the world's longest-lived trees, sometimes growing for over 1,000 years! The oldest known oak tree is in the southern United States and is over 1,500 years old. Oaks produce an exceedingly popular type of wood which is used to make different products, from furniture and flooring to wine barrels and even cosmetic creams.
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About
Key Facts
Distribution
How To Care
All Species
More Genus
Knotweeds
Polygonum
The knotweeds (Polygonum) are a sizable and diverse group of mostly temperate flowering plants. Several species within this genus have historically been eaten by humans, although few have been widely cultivated as food sources. One exception to this is Madimak (P. cognatum), which is quite popular as a green in Turkish cuisine, and is today heavily cultivated in the central part of that country. Being hardy, colonizing species that spread quickly, several knotweeds are also considered pesky invasives beyond their native ranges.
Lifespan
Perennial
Key Facts About Knotweeds
Feedback
Attributes of Knotweeds
Leaf type
Semi-evergreen
Trivia and Interesting Facts
This plant was found in Philadelphia around 1910. It is a kind of rice field weed that is hard to remove because of its strong viability in wetlands, river banks, grasslands, moors and mudflats.
Scientific Classification of Knotweeds
Phylum
Vascular plants Class
Dicotyledons Order
Pinks, cacti, and allies Family
Buckwheat Genus
Knotweeds Distribution of Knotweeds
Feedback
Distribution Map of Knotweeds
Native
Cultivated
Invasive
Potentially invasive
Exotic
No species reported
How to Grow and Care for Knotweeds
Feedback
Knotweeds comprises versatile plants with varying care needs. They typically prefer full sun to partial shade, consistent moisture without waterlogging, and thrive in well-draining soils. Gardeners may encounter challenges from pests like aphids and diseases such as powdery mildew. Seasonal care involves mulching for winter protection, pruning in late winter or early spring, and increased watering during hot summers, with reduced frequency in cooler months.
Exploring the Knotweeds Plants
Feedback
8 most common species：
Prostrate knotweed
Prostrate knotweed (Polygonum aviculare) is a low-growing species that can root practically anywhere. It produces many small white flowers each summer and produces plenty of seeds that can survive for years. Its seeds can lay dormant in soils, and once they see sunlight, they will start to germinate. Because it grows so dwarf, mowing is not effective in removing it.
Oval leaf knotweed
Oval leaf knotweed (Polygonum arenastrum) is an invasive plant native to Europe that can now be found throughout North America as well. It sends out a long tap root that helps make it very drought-tolerant. Oval leaf knotweed prefers dense, compacted soils. Though a bane of large-scale farmers, it can usually be pulled by hand in smaller gardens.
Sawatch knotweed
Sawatch knotweed (Polygonum sawatchense) is an annual herb in the buckwheat family that is found throughout western North America. Like other flowering plants in the Polygonum family, this knotweed is known to attract the Purplish Copper Butterfly.
Sea knotgrass
Sea knotgrass is a perennial plant that can be found growing on sand and shingle beaches. The Latin name, Polygonum maritimum, translates to "many joints" (polygonum) and "seashore" (maritimum). These refer to sea knotgrass's thick, woody stems, which the plant is renowned for, as well as the coastal areas it inhabits.
Show More Species
All Species of Knotweeds
More Popular Genus
Feedback
Dracaena
Dracaena are popular house plants that are easy to grow. They can tolerate low-light conditions and require little watering. Their leaves range from variegated to dark green. Their characteristic traits include woody stems that grow slowly but offer a striking appearance for small spaces such as apartments or offices.
Fig trees
Fig trees have been cultivated in many regions for their fruits, particularly the common fig, F. carica. Most of the species have edible fruits, although the common fig is the only one of commercial value. Fig trees are also important food sources for wildlife in the tropics, including monkeys, bats, and insects.
Brambles
Brambles are members of the rose family, and there are hundreds of different types to be found throughout the European countryside. They have been culturally significant for centuries; Christian folklore stories hold that when the devil was thrown from heaven, he landed on a bramble bush. Their vigorous growth habit can tangle into native plants and take over.
Maples
The popular tree family known as maples change the color of their leaves in the fall. Many cultural traditions encourage people to watch the colors change, such as momijigari in Japan. Maples popular options for bonsai art. Alternately, their sap is used to create maple syrup.
Prunus
Prunus is a genus of flowering fruit trees that includes almonds, cherries, plums, peaches, nectarines, and apricots. These are often known as "stone fruits" because their pits are large seeds or "stones." When prunus trees are damaged, they exhibit "gummosis," a condition in which the tree's gum (similar to sap) is secreted to the bark to help heal external wounds.
Nightshades
Nightshades is a large and diverse genus of plants, with more than 1500 different types worldwide. This genus incorporates both important staple food crops like tomato, potato, and eggplant, but also dangerous poisonous plants from the nightshade family. The name was coined by Pliny the Elder almost two thousand years ago.
Roses
Most species of roses are shrubs or climbing plants that have showy flowers and sharp thorns. They are commonly cultivated for cut flowers or as ornamental plants in gardens due to their attractive appearance, pleasant fragrance, and cultural significance in many countries. The rose hips (fruits) can also be used in jams and teas.
Oaks
Oaks are among the world's longest-lived trees, sometimes growing for over 1,000 years! The oldest known oak tree is in the southern United States and is over 1,500 years old. Oaks produce an exceedingly popular type of wood which is used to make different products, from furniture and flooring to wine barrels and even cosmetic creams.
Your Ultimate Guide to Plants
Identify grow and nurture the better way!
17,000 local species +400,000 global species studied
Nearly 5 years of research
80+ scholars in botany and gardening
Continue reading in our app - it's better
A database of 400000+ plants
unlimited guides at your fingertips...
unlimited guides at your fingertips...
