Purple Loosestrife, purple lythrum, bouquet-violet, spiked loosestrife
Description: herbaceous perennial
Place of origin: Eurasia
Urban habitat: commonly found at the edges of wetlands and meadows, in drainage ditches, along highways; tolerant of a wide range of soil conditions, including high pH and salinity; seeds can remain viable in soil for many years before sprouting.
Ecological function: disturbance-adapted colonizer; absorbs nutrients in wetlands, can provide stream and riverbank stabilization.
History: Lythrum salicaria was first reported to be seen in North America in 1814, introduced in the northeast either accidentally via ship ballast from Europe or deliberately, for practical and ornamental reasons. The plant spread rapidly after 1930 due to agricultural settlements and highway construction. It is now considered to be one of the most noxious and invasive weeds in the US, although it continues to be planted as an ornamental in many states. Once established, it can form dense monocultures that displace native plants species and threaten wildlife wetland habitats. Many chemical and biological methods of control have been used and studied as a means of limiting the spread of the plant, including the introduction of predator insects from its native range. The plant was used medicinally in Europe for treatment of diarrhea, dysentery, and as an astringent to wash wounds. It has also been used to treat heavy menstrual bleeding as well as nosebleeds. Modern research has shown the plant to be antibiotic and an effective treatment against the micro-organism that causes typhus. Its flowers are used by beekeepers to provide a source of nectar to make honey.