![]() ![]() Older plants can be removed with a shovel. Small infestations of young purple loosestrife plants may be pulled by hand, preferably before seed set. Many new stems may emerge vegetatively from a single rootstock of the previous year. Purple loosestrife also readily reproduces vegetatively through underground stems at a rate of about one foot per year. A mature plant may have as many as thirty flowering stems capable of producing an estimated two to three million, minute seeds per year. The flowers require pollination by insects, for which it supplies an abundant source of nectar. Purple loosestrife enjoys an extended flowering season, generally from June to September, which allows it to produce vast quantities of seed. They can be moved longer distances by water or by becoming attached to waterfowl. The seeds usually fall to the ground after they have ripened. Lythrum salicaria reproduces through prolific seed dispersal. These seeds persist in the seed bank for years, even if the plants themselves are eradicated from an area. Lythrum salicaria can produce up to 2.5 million seeds per plant. By forming these dense stands, Lythrum salicaria can clog waterways, causing problems for both commercial and recreational uses of these areas. It can also have an effect on native wildlife that may not be able to use the plants as effectively for food or cover. These stands prevent the establishment of native wetland plants. ![]() Purple loosestrife has the ability to completely dominate wetlands, forming a vast, monotypic stands an area dominated by a single species. Since these initial introductions it has spread by being planted in gardens and by waterways. By the 1900's there were more inland populations being reported, one of these being in New Hampshire. Lythrum salicaria was also planted as a source of nectar for beekeeping, as an ornamental, and for medicinal reasons. It could have been a part of ship ballast from Europe, or attached to sheep. There are several hypotheses on how this plant was originally introduced. The location of these sites would indicate that the plant was introduced somewhere in this area. Before the year 1900, 14 of 30 populations of this plant were located in estuaries from Massachusetts to New Jersey. The first report of Lythrum salicaria in North America was in 1814. In recently-disturbed wetlands such as drawn-down ponds and abandoned beaver ponds and pastures, loosestrife may be highly dominant. Loosestrife can establish on recently disturbed upland soils, although it remains smaller there than in wetlands. It is also common in fresh and brackish tidal wetlands. Purple loosestrife is a plant of freshwater wetlands, including marshes, wet meadows, fens, bogs, openings in forested swamps, intermittent streams and pools, pond and lake shores, stream banks, and ditches. However, it prefers areas with shallow water, and does not grow as prolifically in deep-water situations. Purple loosestrife is most often found in situations where the soil is moist. The fruits are capsules, each containing numerous reddish-brown seeds. The flowers are in bloom from July to September. Each flower has 5-7 petals, and the open flowers measure 0.3-0.5 inches in diameter. The hypanthium is linear and twice as long as the sepals. They are numerous and borne on spikes that are between 4-16 inches long. The larger leaves can be cordate or clasping at their bases. They are lanceolate shaped like the head of a lance of a narrow oval shape tapering to a point at each end to linear in shape and 1-4 inches long. ![]() They can be pubescent soft down or fine short hairs on the leaves and stems of plants or glabrous smooth free from hairs. The leaves are either opposite or in whorls of three. Purple loosestrife is an herbaceous wetland perennial a plant whose growth dies down annually but whose roots or other underground parts survive that can grow 1.5-5 feet tall. ![]()
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