UCONN IPM: Biological Control: Purple Loosestrife:Poster2

Purple Loosestrife

loosestrife poster 2 Purple loosestrife (Lythrum salicaria) is an invasive non-native plant from Europe and Asia that was introduced into North America almost 200 years ago. The largest occurrences of this species are found in wetlands in the northeastern U.S., including all counties in Connecticut. When purple loosestrife aggressively moves into wetlands, it eliminates native plants such as cattails, sedges, bulrush and ferns. As these wetlands become infested with purple loosestrife, desirable food and nesting sites for wildlife are lost and there are fewer stopover sites for migrating birds.
PLANT DESCRIPTION
Purple loosestrife is a herbaceous perennial that may grow up to 10 feet tall and 4 feet wide. Plants can reach maturity in 3 to 5 years, producing as many as 50 stems per plant. Leaves have smooth edges and are arranged opposite in pairs or in whorls of three. The leaves are lance-shaped and directly attached to stems. Stems are usually square, but may become five-or six-sided and woody as plants mature. Leaves and stems of purple loosestrife may be smooth or covered with soft hairs. Purple loosestrife blooms during the summer months. The reddish-purple flowers, each with 5 to 7 petals, are produced on a tall inflorescence.

Purple Loosestrife Cultivars are NOT STERILE
Researchers have determined that purple loosestrife ornamental cultivars are not sterile, but are, in fact, very fertile. All purple loosestrife cultivars can serve as pollen or seed sources. Purple loosestrife is insect pollinated. When bees, wasps or butterflies visit these garden plants, the insects carry pollen to purple loosestrife plants in nearby wetlands, adding to the spread of this invasive species in natural areas. With one purple loosestrife plant producing as many as 2.5 million seeds each year, an acre of purple loosestrife yielding up to 24 billion seeds per year, and seeds remaining viable in the ground for at least 5 years, even a few plants can pose a serious threat to the environment.

Purple Loosestrife
Purple loosestrife (Lythrum salicaria) is an invasive non-native plant from Europe and Asia that was introduced into North America almost 200 years ago. The largest occurrences of this species are found in wetlands in the northeastern U.S., including all counties in Connecticut. When purple loosestrife aggressively moves into wetlands, it eliminates native plants such as cattails, sedges, bulrush and ferns. As these wetlands become infested with purple loosestrife, desirable food and nesting sites for wildlife are lost and there are fewer stopover sites for migrating birds. PLANT DESCRIPTION Purple loosestrife is a herbaceous perennial that may grow up to 10 feet tall and 4 feet wide. Plants can reach maturity in 3 to 5 years, producing as many as 50 stems per plant. Leaves have smooth edges and are arranged opposite in pairs or in whorls of three. The leaves are lance-shaped and directly attached to stems. Stems are usually square, but may become five-or six-sided and woody as plants mature. Leaves and stems of purple loosestrife may be smooth or covered with soft hairs. Purple loosestrife blooms during the summer months. The reddish-purple flowers, each with 5 to 7 petals, are produced on a tall inflorescence. Purple Loosestrife Cultivars are NOT STERILE Researchers have determined that purple loosestrife ornamental cultivars are not sterile, but are, in fact, very fertile. All purple loosestrife cultivars can serve as pollen or seed sources. Purple loosestrife is insect pollinated. When bees, wasps or butterflies visit these garden plants, the insects carry pollen to purple loosestrife plants in nearby wetlands, adding to the spread of this invasive species in natural areas. With one purple loosestrife plant producing as many as 2.5 million seeds each year, an acre of purple loosestrife yielding up to 24 billion seeds per year, and seeds remaining viable in the ground for at least 5 years, even a few plants can pose a serious threat to the environment.

For more information contact Donna Ellis, State Survey Coordinator, University of Connecticut Department of Plant Science, Telephone (860)486-6448; FAX (860)486-0682; email address: donna.ellis@uconn.edu

Links: CERIS (Center for Environmental and Regulatory Information Systems)

This information was developed for conditions in the Northeast. Use in other geographical areas may be inappropriate.

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