Polygonum majus | |
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Scientific classification ![]() | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Caryophyllales |
Family: | Polygonaceae |
Genus: | Polygonum |
Species: | P. majus |
Binomial name | |
Polygonum majus | |
Synonyms [1] | |
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Polygonum majus is a North American species of flowering plant in the buckwheat family known by the common name wiry knotweed. It grows in the western United States and western Canada, from British Columbia south as far as the Sierra Nevada of northwestern Inyo County in California, east as far as Montana. [2] [3] Knotweed is a spreading, wiry annual weed that rarely grows higher than a few inches. The leaves are tiny, oblong, bluish-green, and 14 inches broad and 1 inch long. The flowers are tiny and unobtrusive, whitish-green in colour, and appear in the leaf axils in the fall. Knotweed may grow into a dense mat with a diameter of up to three feet, strangling out ideal grass and plants. [3] The branches of this evergreen plant form a strong, wiry mat that reaches barely a few centimeters above the earth. [4] They appear constantly, and gardeners are always fighting them. [2]
Polygonum majus is an herb up to 60 cm (2 feet) tall. Stems are thin and wiry. Flowers are white or pink. [4] [5] Knotweed is distinguished by its upward, splitting branches and lateral phenotypic expression. The branches of this grassy plant form a strong, wiry mat that reaches barely a few millimeters above the earth. Knotweed may grow vertically on occasion, mainly on lawns with greater shade. Knotweed has slender stems that are branching and bulging at the nodes, as well as a thin taproot. Knotweed is a brief perennial that spreads its wiry stems outward from a central taproot in a thick mat of tensile stems interrupted by tiny joints or tangles. Small blue-green leaves are green regularly from the base to the top of those stalks. [4] There are two varieties of knotweed. Polygonum arenastrum, popularly known as wiregrass, wireweed, matweed, or doorweed, grows flat and spreads outward in a dense circular shape that can measure 18 inches (46 cm) wide with a slender taproot that can develop as thick as 18 inches (46 cm). It seldom grows taller than a couple inches (8 cm). Silver coated knotweed, Polygonum argyrocoleon, reaches a height of one foot (31 cm.) or more. It produces tall spikes with floral flowers. Garden spurge is frequently confused with knotweed by gardeners. When you recall that the trumpet vine emits a milky liquid when split, while knotweed does not, it's easy to tell them apart. [3] [2] [5] [4]
Taxonomy
Polygonum majus is the scientific name for this plant (Meisn.) Piper belongs to the Polygonaceae family. Palouse knotweed, wiry knotweed, Eastern Washington, and Native are some of the popular names for this plant. There are no synonyms for this word, and it has no conservation status. [2] [3]
Distribution and Habitat
Although it is one of the earliest summer perennial broadleaf weeds to appear in the spring, it can appear at any time during the spring and summer. Knotweed may thrive on lawns with a diverse combination of shadow and sunshine, but it must sprout in wet soil. Knotweed may be found all over the United States, although it thrives on compacted soils. Polygonum aviculare is its scientific name. Knotweed is distinguished by its rising, spreading branches and lateral developmental stages. [4] Although hand-pulling is a viable short-term strategy for eradicating Polygonum aviculare, it is not the most productive. Knotweed reproduces by producing tiny seeds (less than 1/25 of an inch). Touch can dislodge seeds from their capsules, allowing them to disperse over the grass. The most accurate means for management is to use properly chosen and administered broadleaf weed killers that are tailored to local geography and climate. [3] Common knotweed thrives in farm land, breeding grounds, and other disturbed sites, even in weak and compressed soil. Exploitative insects are typically attracted to this plant. Japanese knotweed may be found in sunny spots inside landscapes that have been purposefully planted, along roadsides, and in riparian habitats like stream beds. Knotweeds can thrive in a variety of soil types and brightness, though they won't be as hardy if they're in the shade. [3]
Cultural Significance
Although this plant is fertilized by insects and develops spores that are distributed by the breeze, it is the Knotweed roots (known as rhizomes) that distinguish this invasive species and are responsible for the majority of its dissemination and harm. Rhizomes are altered, fleshy branches that run horizontal underneath and may transmit root system as well as additional stems above surface; it's an efficient method used by a variety of troublesome plants. It's also why using a tarp to suffocate Knotweed is futile. In 2016, researchers in England conducted the first part of the world's largest Japanese Knotweed field study, which tested control measures. Regardless of the fact that no treated group achieved total elimination within three years, the herbicide glyphosate (a.k.a. Roundup) proved to be the most effective therapy when administered at the proper expansion phase and with the proper dose and distribution (both sprayed and injected). [3] The herbicide glyphosate requires three to five years to manage, and its usage in New England may be susceptible to municipal permit and advertising regulations if it is near wetlands. Discontinue the use of certain extensively used weedkillers superfluous physical control strategies (cutting and replace, summertime mowing, and trench) that add gear and labour costs while increasing environmental consequences, without increasing control comparison to application alone," the researchers added.
Reynoutria japonica, synonyms Fallopia japonica and Polygonum cuspidatum, is a species of herbaceous perennial plant in the knotweed and buckwheat family Polygonaceae. Common names include Japanese knotweed and Asian knotweed. It is native to East Asia in Japan, China and Korea. In North America and Europe, the species has successfully established itself in numerous habitats, and is classified as a pest and invasive species in several countries.
Herbicides, also commonly known as weed killers, are substances used to control undesired plants, also known as weeds. Selective herbicides control specific weed species while leaving the desired crop relatively unharmed, while non-selective herbicides can be used to clear waste ground, industrial and construction sites, railways and railway embankments as they kill all plant material with which they come into contact. Apart from selective/non-selective, other important distinctions include persistence, means of uptake, and mechanism of action. Historically, products such as common salt and other metal salts were used as herbicides, however, these have gradually fallen out of favor, and in some countries, a number of these are banned due to their persistence in soil, and toxicity and groundwater contamination concerns. Herbicides have also been used in warfare and conflict.
Weed control is a type of pest control, which attempts to stop or reduce growth of weeds, especially noxious weeds, with the aim of reducing their competition with desired flora and fauna including domesticated plants and livestock, and in natural settings preventing non native species competing with native species.
Persicaria is a genus of herbaceous flowering plants in the knotweed family, Polygonaceae. Plants of the genus are known commonly as knotweeds or smartweeds. It has a cosmopolitan distribution, with species occurring nearly worldwide. The genus was segregated from Polygonum.
Solanum carolinense, the Carolina horsenettle, is not a true nettle, but a member of the Solanaceae, or nightshade family. It is a perennial herbaceous plant, native to the southeastern United States, though its range has expanded throughout much of temperate North America. The plant is an invasive in parts of Europe, Asia, and Australia. The stem and undersides of larger leaf veins are covered with prickles.
Polygonum is a genus of about 130 species of flowering plants in the buckwheat and knotweed family Polygonaceae. Common names include knotweed and knotgrass. In the Middle English glossary of herbs Alphita, it was known as ars-smerte. There have been various opinions about how broadly the genus should be defined. For example, buckwheat has sometimes been included in the genus as Polygonum fagopyrum. Former genera such as Polygonella have been subsumed into Polygonum; other genera have been split off.
Polygonum arenastrum, commonly known as equal-leaved knotgrass, is a summer annual flowering plant in the knotweed family Polygonaceae. Other common names include common knotweed, prostrate knotweed, mat grass, oval-leaf knotweed, stone grass, wiregrass, and door weed, as well as many others. It is native to Europe and can be found on other continents as an introduced species and a common noxious weed. Knotweed was first seen in North America in 1809 and is now seen across much of the United States and Canada.
Polygonum aviculare or common knotgrass is a plant related to buckwheat and dock. It is also called prostrate knotweed, birdweed, pigweed and lowgrass. It is an annual found in fields and wasteland, with white flowers from June to October. It is widespread across many countries in temperate regions, apparently native to Eurasia, naturalized in temperate parts of the Southern Hemisphere.
A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals. Plants with characteristics that make them hazardous, aesthetically unappealing, difficult to control in managed environments, or otherwise unwanted in farm land, orchards, gardens, lawns, parks, recreational spaces, residential and industrial areas, may all be considered weeds. The concept of weeds is particularly significant in agriculture, where the presence of weeds in fields used to grow crops may cause major losses in yields. Invasive species, plants introduced to an environment where their presence negatively impacts the overall functioning and biodiversity of the ecosystem, may also sometimes be considered weeds.
Bryonia alba is a vigorous vine in the family Cucurbitaceae, found in Europe and Northern Iran. It has a growth habit similar to kudzu, which gives it a highly destructive potential outside its native range as a noxious weed. Other common names include false mandrake, English mandrake, wild vine, and wild hops, wild nep, tamus, ladies' seal, and tetterbury.
Polygonum bidwelliae is an uncommon species of flowering plant in the knotweed family known by the common name Bidwell's knotweed. The plant was named for American suffragist Annie Bidwell, who at one time lived in the Bidwell Mansion in Chico, California. She is the person who collected the type specimen in Northern California.
Polygonum californicum is a species of flowering plant in the buckwheat family known by the common name California knotweed. It is native to the west coast of the United States from Washington, Oregon, and northern and central California in the Coast Ranges and Sierra Nevada foothills as far south as Napa and Tulare Counties. It can be found in many types of open habitats.
Polygonum parryi is a species of flowering plant in the knotweed family known by the common names Parry's knotweed and prickly knotweed. It is native to the western United States from Washington to California, where it grows in several types of moist, open habitat in mountainous and coastal areas.
Polygonum polygaloides is a North American species of flowering plants in the buckwheat family known by the common names milkwort knotweed and polygala knotweed. It is native to much of western North America, where it can be found in many types of moist habitat. It is a variable species, usually divided into a number of subspecies.
Polygonum albanicum is a flowering herbaceous plant of the knotweed family. It is a trans-regional species primarily found in Albania and recently in its neighboring countries.
Polygonum basiramia is a rare species of flowering plant in the knotweed family known by the common names wireweed, hairy wireweed, purple wireweed, and Florida jointweed. It is endemic to Florida in the United States, where it is limited to the central ridges of the peninsula, including the Lake Wales Ridge. It is threatened by the loss and degradation of its habitat. It is a federally listed endangered species of the United States.
Panicum repens is a species of grass known by many common names, including torpedograss, creeping panic, panic rampant, couch panicum, wainaku grass, quack grass, dog-tooth grass, and bullet grass. Its exact native range is obscure. Sources suggest that the grass is native to "Africa and/or Asia", "Europe or Australia", "Eurasia", "Australia", "Europe, Asia, and Africa", or other specific regions, including the Mediterranean, Israel, and Argentina. It is present in many places as an introduced species and often a noxious weed. It has been called "one of the world's worst weeds."
Koenigia phytolaccifolia is a species of flowering plant in the knotweed family, known by the common name poke knotweed.
Koenigia polystachya is a species of flowering plant in the knotweed family, known by the common names Himalayan knotweed and cultivated knotweed. It has several regularly used synonyms, including Polygonum polystachyum, Aconogonon polystachyum and Persicaria wallichii.
Polygonum spergulariiforme is a North American species of flowering plants in the buckwheat family known by the common name spurry knotweed or fall knotweed. It grows in western Canada and the western United States.