Common knotgrass | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Caryophyllales |
Family: | Polygonaceae |
Genus: | Polygonum |
Species: | P. aviculare |
Binomial name | |
Polygonum aviculare L. 1753 | |
Synonyms [1] | |
Synonymy
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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. [2] [3] [4] [5] [6] [7]
Common knotgrass is an annual herb with a semi-erect stem that may grow from 10 to 40 cm (4 to 16 in) high. The leaves are hairless and short-stalked. They are longish-elliptical with short stalks and rounded bases; the upper ones are few and are linear and stalkless. The stipules are fused into a stem-enclosing, translucent sheath known as an ochrea that is membranous and silvery. The flowers are regular, green with white or pink margins. Each has five perianth segments, overlapping at the base, five to eight stamens and three fused carpels. The fruit is a dark brown, three-edged nut. The seeds need light to germinate which is why this plant appears in disturbed soil in locations where its seeds may have lain dormant for years. It is a common carrier of the parasitic pathogen powdery mildew, [8] which can give the leaves a whitish appearance. [3] [9]
Polygonum aviculare has a wide distribution as an arable weed and plant of fields, shingle, sand, roadsides, yards and waste places. There is much morphological variation among different populations and several different sub-species are recognized: [1] [2] [3] [9]
Widespread and common in Great Britain, [10] Ireland, [10] [11] and Scandinavia. [12]
It is common on roadsides and arable ground in the British Isles. [11]
Polygonum aviculare contains the flavonols avicularin, myricitrin and juglanin. [13] The flavanoids astragalin and betmidin, and the lignan aviculin have also been found. [14] The diterpene alkaloid panicudine is another known component. [15]
One fossil fruit of Polygonum aviculare has been extracted from borehole samples of the Middle Miocene fresh water deposits in Nowy Sacz Basin, West Carpathians, Poland. [16]
It formed a traditional ingredient in porridge consumed by Germanic peoples of western Europe, and has been found in numerous autopsies of peat bodies, including the Tollund Man.
In Vietnam, where it is called rau đắng, it is widely used to prepare soup and hot pot, particularly in the southern region.
Rubus is a large and diverse genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae, with over 1,350 species, commonly known as brambles.
Campanula is the type genus of the Campanulaceae family of flowering plants. Campanula are commonly known as bellflowers and take both their common and scientific names from the bell-shaped flowers—campanula is Latin for "little bell".
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.
Persicaria maculosa is an annual plant in the buckwheat family, Polygonaceae. Common names include lady's thumb, spotted lady's thumb, Jesusplant, and redshank. It is widespread across Eurasia from Iceland south to Portugal and east to Japan. It is also present as an introduced and invasive species in North America, where it was first noted in the Great Lakes region in 1843 and has now spread through most of the continent.
Stratiotes is a genus of submerged aquatic plant commonly known as water soldiers, described as a genus by Linnaeus in 1753. Several specific names have been coined within the genus, but at present only one is recognized: Stratiotes aloides. native to Europe and NW Asia.
Cyperus is a large genus of about 700 species of sedges, distributed throughout all continents in both tropical and temperate regions.
Phyllanthus is the largest genus in the plant family Phyllanthaceae. Estimates of the number of species in this genus vary widely, from 750 to 1200. Phyllanthus has a remarkable diversity of growth forms including annual and perennial herbs, shrubs, climbers, floating aquatics, and pachycaulous succulents. Some have flattened leaflike stems called cladodes. It has a wide variety of floral morphologies and chromosome numbers and has one of the widest range of pollen types of any seed plant genus.
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.
Persicaria lapathifolia, known as pale persicaria, is a plant of the family Polygonaceae. It is closely related to Persicaria maculosa and as such is considered a weed in Britain and Europe. Other common names for the plant include pale smartweed, curlytop knotweed, and willow weed. It is a species complex made up of a great many varying forms, sometimes considered varieties. The environment also has a strong influence on the morphology of an individual plant.
Hydrocotyle, also called floating pennywort, water pennywort, Indian pennywort, dollar weed, marsh penny, thick-leaved pennywort and white rot, is a genus of prostrate, perennial aquatic or semi-aquatic plants formerly classified in the family Apiaceae, now in the family Araliaceae.
Equisetum arvense, the field horsetail or common horsetail, is an herbaceous perennial plant in the Equisetidae (horsetails) sub-class, native throughout the arctic and temperate regions of the Northern Hemisphere. It has separate sterile non-reproductive and fertile spore-bearing stems growing from a perennial underground rhizomatous stem system. The fertile stems are produced in early spring and are non-photosynthetic, while the green sterile stems start to grow after the fertile stems have wilted and persist through the summer until the first autumn frosts. It is sometimes confused with mare's tail, Hippuris vulgaris.
Polygonum ramosissimum is a North American species of herbaceous annual plants in the buckwheat family, widespread across much of Canada and the United States, where it is commonly called bushy knotweed. It is susceptible to downy mildew caused by the oomycete species Peronospora americana.
Najas marina is a species of aquatic plant known by the common names spiny water nymph, spiny naiad and holly-leaved naiad. It is an extremely widespread species, reported across Europe, Asia, Africa, Australia, the Americas and many oceanic islands. It can be found in many types of freshwater and brackish aquatic habitat, including bodies of alkaline water.
British NVC community OV3 is one of the open habitat communities in the British National Vegetation Classification system. It is one of six arable weed and track-side communities of light, less-fertile acid soils.
British NVC community OV7 is one of the open habitat communities in the British National Vegetation Classification system. It is one of eight arable weed and wasteland communities of fertile loams and clays.
British NVC community OV8 is one of the open habitat communities in the British National Vegetation Classification system. It is one of eight arable weed and wasteland communities of fertile loams and clays.
British NVC community OV13 is one of the open habitat communities in the British National Vegetation Classification system. It is one of eight arable weed and wasteland communities of fertile loams and clays.
British NVC community OV17 is one of the open habitat communities in the British National Vegetation Classification system. Although classed with communities OV15 and OV16 as an arable weed community of light lime-rich soils, it also shares many features with the communities classed as arable weed and wasteland communities of fertile loams and clays.
Polygonum fowleri, commonly called Fowler's knotweed or Hudsonian knotweed, is a plant species native to the seashores of the northern part of North America. It has been reported from every Canadian province and territory except Alberta and Saskatchewan, as well as from Maine, Alaska, Washington, Oregon, California, and St. Pierre & Miquelon. It is usually found in gravelly locations along the seacoast.
Polygonum oxyspermum is a coastal species of flowering plant in the buckwheat family. It is native to Europe, primarily along the shores of the Atlantic, the North Sea, and the Baltic Sea, from France and Ireland to Finland and Russia. It is also naturalized in eastern Canada and in the US State of Maine.