The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—buckwheat family in the United States. The name is based on the genus Polygonum, and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name may refer to the many swollen nodes the stems of some species have, being derived from Greek [poly meaning 'many' and gony meaning 'knee' or 'joint']. Alternatively, it may have a different origin, meaning 'many seeds'.
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.
Persicaria lapathifolia, known as pale persicaria, is a plant of the family Polygonaceae. It is considered to be native throughout most of the world, from arctic to tropical realms, except South America and Southern Africa. 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.
Banksia rufa is a species of prostrate shrub that is endemic to the south-west of Western Australia. It has broadly linear, pinnatifid or pinnatipartite leaves with between five and twenty lobes on each side, yellow, orange or brownish flowers in heads of forty or more, and glabrous, egg-shaped follicles.
Banksia ionthocarpa is a species of shrub that is endemic to Western Australia. It has short, hairy, prostrate stems, pinnatifid leaves, pinkish purple to orange flower in heads of between forty and sixty at the base of leaves, and egg-shaped follicles with a distinctive tuft of hairs on the end.
Montia fontana, blinks is a herbaceous annual to perennial plant that grows in freshwater springs in upland regions, and in seasonally damp acid grassland in the lowlands. It is widespread throughout the world, except in southern Asia. It is rather variable in morphology, which is reflected in a complex history of taxonomy. Currently, there are three accepted subspecies which are defined largely by the appearance of the seedcoat. It is edible and consumed as a salad in some areas, but is otherwise of minimal economic impact. Because of its association with clean water habitats, it is often viewed as a species of conservation value.
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.
Persicaria amphibia is a species of flowering plant in the knotweed family known by several common names, including longroot smartweed, water knotweed, water smartweed, and amphibious bistort. It is native to much of North America, Asia, Europe, and parts of Africa, and it grows elsewhere as an introduced species and sometimes a noxious weed.
Polygonum marinense is a rare North American species of flowering plants in the buckwheat family known by the common name Marin knotweed. It is endemic to California, where it is known from just a few locations north and east of San Francisco Bay.
Polygonum minimum is a species of flowering plant in the knotweed family known by the common name broadleaf knotweed. It is native to much of western North America where it can be found in mountainous regions. It grows in the subalpine and alpine climates of high mountain ranges from Alaska to Arizona and New Mexico.
Polygonum paronychia is a species of flowering plant in the knotweed family known by the common names dune knotweed, black knotweed, and beach knotweed. It is native to the coastline of western North America from British Columbia to California, where it grows in sandy coastal habitat such as beaches, dunes, and scrub.
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 shastense is a species of flowering plant in the knotweed family known by the common name Shasta knotweed. It is native to sections of southwestern Oregon, northwestern Nevada, and northern and central California, where it grows in rocky and gravelly mountainous habitat up to 3300 meters (11,000 feet) elevation. It is most common in the Sierra Nevada. The species name refers to its occurrence on Mount Shasta in Shasta County, California.
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 cognatum, commonly called Indian knotgrass or madimak, is an edible weedy creeping perennial herb in the genus Polygonum, frequently eaten by people of Turkey. It has larger leaves than most other species of Polygonum.
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.
Koenigia davisiae is a flowering plant in the knotweed family that is known by the common names Davis' knotweed or Newberry knotweed.
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.
