Knotweed

Japanese knotweed, for example, was introduced into British gardens in 1825, as "a plant of sterling merit." It is now Britain s most troublesome weed, and a serious problem in parts of North America, too. 

Polygonum cuspidatum Siebold Zucc. Hu Chang (J apanese knotweed) (stem, root) Polygonin, glucofragulin, emodin, polydatin, flavonoids.33 Treat hypercholesterol. 

P. pensylvanicum, also called Pennsylvania smartweed or Pennsylvania knotweed, is a common plant in the eastern U.S.2 It grows in drainage ditches, fallow fields, and other uncultivated areas. Originally collected in 1968 as part of the National Cancer Institute (NCI)... 

California trees, citrus tree trunk and canopy growth, leaf nitrogen level, fruit yield, and fruit quality were decreased by competition from annual weeds and bermudagrass (Jordan, 1981). Suzuki (1981) reported that in Japan, weeds in summer absorb and transpire large amounts of water from the soil and compete with citrus trees. Moisture and nitrogen levels in the soil decreased particularly where large crabgrass and tufted knotweed were present (Ito and Ukei, 1981). 

Polygonum caespitosum Blume var. longisetum (DeBruyn) A.N. Stewart knotweed, tufted... 

Jerusalem artichoke had a similar methane production potential for repeated cuttings in the Finnish trials, whereas other leafy energy crops assessed, such as giant knotweed (Reynoutria sachalinensis F. Schmidt ex Maxim.) and sugar beet tops (Beta vulgaris L.), had methane potentials that increased at later harvests. Lignin levels were also unusually constant for the tops of Jerusalem artichoke, regardless of maturity, while nonstructural carbohydrates (fructans) increased in the stems... 

Two naphthoquinones, emodin (65) and physcion (66), and their glucosides were identified as allelochemicals from the rhizomes, aerial parts, and fallen leaves of giant knotweed (Polygonum sachalinense Fr. Schm.).7 In addition, the concentrations of emodin and physcion in the soil samples collected from the weed community were high enough to suppress seedling growth of susceptible plant species. 

Mycorrhizae are a common type of mutualism about 90% of the families of vascular plants live in this sort of beneficial relationship with fungi. Only a few economically important plant families do not develop mycorrhizae, among them the mustards (family Brassi-caceae) and knotweeds (Polygonaceae). 

Pilocarpus species (pilocarpus) Piper methysticum (kava kava) Pithecollobium jiringa (jering fruit) Plantago species (plantain) Polygonum (knotweed)... 

Knotweed Polygonum Venus flytrap Dionaea muscipula... 

Kala, C.P. (2004). Pastoralism, plant conservation, and conflicts on proliferation of Himalayan Knotweed in high altitude protected areas of the Western Himalaya, India. Biodiversity and Conservation, 13 (5) 985-995. 

Herbicidal activity on several weeds, such as hairy beggarsticks, black nightshade, and knotweed, was reported in 2004 for a series of 2,4,5-imidazolidine triketones, such as compound 92 [100] (Fig. 3.25). 

A similar effect is now as well ascribed to resveratrol, aphytoalexin from the skin of black grapes, and to the Japanese knotweed (Polygonum cuspidatum). The active compound, widely used in traditional Chinese herhal medicine, prevents the increased expression of human cyclooxygenase-2 and hence a higher COX-2 activity. 

English name Prostrate knotweed. Yard knotweed... 

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