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Purple loosestrife (Lythrum salicaria)—also known as Spiked loosestrife, Purple lythrum, Rainbow weed or Salicaire—is a semi-aquatic herbaceous plant belonging to the loosestrife family, Lythraceae. A perennial native to the wetlands of Eurasia, Purple loosestrife has become an important invasive species since its introduction into temperate North America where it is now considered a noxious weed. It should not be confused with other plants sharing the name loosestrife that are members of the Primrose family, Primulaceae.
Once enjoyed as a medicinal herb and as an attractive garden plant, purple loosestrife has had a destructive impact on North American wetland ecology since the early 19th century. The plants grow vigorously and spread alarmingly fast, far removed from their natural controlling agents. Infestations result in dramatic disruption in water flow in rivers and canals, and a sharp decline in biological diversity. Native food and cover plant species, notably the cattails, are completely crowded out.
Purple loosestrife may rise two metres in height and 1.5 metres in width with up to 50 erect stalks to a single woody root mass. The wide, downy and sessile leaves are 3-10 centimetres in length and opposite in two ranks. Although easily identified during its blooming season from JuneJune is the sixth month of the year in the Gregorian Calendar, with 30 days. June is named for the Roman goddess Juno, wife of Jupiter. Events in June The solstice occurs around the 21st of this month, although it may occur on either the 20 or 22. It is t to SeptemberSeptember is the ninth month of the year in the Gregorian Calendar, with 30 days. The name comes from the Latin septem for " seven" September was originally the seventh month of the year, before January and February were inserted. In Greek civilization, S, purple loosestrife may be distinguished from similar native plants (i.e. fireweedEpilobium angustifolium Fireweed or (mainly in British English formal botanical texts) Rosebay Willowherb Epilobium angustifolium is a perennial herbaceous plant in the Willowherb family ( Onagraceae). Some botanists separate the species off from the othe, Epilobium angustifolium; blue vervain , Verbena hastata; blazing stars , Liatris spp. and spirea , Spiraea douglasii) by its angular stalks which are square in outline.
The distinctive, showy spires of reddish purple flowers are clustered tightly in the axil s of bractIn botany, a bract is a modified or specialized leaf, from the axil of which a flower or flower stalk arises; or a bract may be any leaf associated with an inflorescence. Usually bracts are green and resemble the other leaves. However, some bracts are bris or leaves; the flowers have 5-6 petals. After their long blooming period the plant's leaves turn bright red through dehydration. Occurring in early autumn, the red colour may last for almost two weeks. The dead stalks from previous growing seasons are also a distinctive shade of brown.
Purple loosestrife invading an old Erie CanalThe Erie Canal (also known since 1918 as the Barge Canal is a canal in New York State, United States, that runs from the Hudson River to Lake Erie, connecting the Great Lakes with the Atlantic Ocean. Although the canal was first proposed in 1699, it was n lock, Durhamville, New York
A single plant may produce up to three million tiny seeds annually. Easily carried by wind and water, the seeds germinate in moist soils after overwintering. Once established, infestations are extremely difficult and costly to remove by mechanical and chemical means. An alternative has been sought in biological pest controlBiological control of pests and diseases Overview A key belief of the organic gardener is that diversity furthers health. The more variety a landscape has, the more sustainable it is. The organic gardener therefore works to create a system where the insec; the release of insects into North America known to feed exclusively on purple loosestrife has met with considerable success. Use of the four insect species - two beetleAdephaga Archostemata Myxophaga Polyphaga many subgroups see Subgroups of the order Coleoptera For alternate meanings see: Beetle (disambiguation Beetles (order Coleoptera are one of the main groups of insects. The order has more species in it than any ots (Galerucella calmariensis and G. pusilla) and two weevils (Hylobius transversovittatus and Nanophyes marmoratus) provides an effective alternative to harmful herbicides in sensitive ecosystems.
See also: List of introduced species
