Lythrum Salicaria
Purple Loosestrife  


Perennial or woody half-shrub.
Purple loosestrife is a shrub-like plant with stiff, four-sided stems ending in spikes of showy purple flowers. Short, narrow leaves are stalkless. Plants become taller and bushier over the years as the rootstock matures, growing to 3 m in height.

Purple loosestrife is an ornamental which has escaped and now occupies wetlands, stream banks, and shallow ponds. It can form dense stands that reduce plant and animal diversity in wetland ecosystems.

Purple loosestrife is found in wet areas at low to mid-elevation in BC, where it grows in ditches, irrigation canals, marshes, stream and lake shorelines, and wetlands. It can tolerate a wide range of conditions and will even grow in standing water. It is common in the Lower Fraser Valley and frequent on southern Vancouver Island and in the Okanagan. There are also localized patches in the Kootenay and Omineca regions.

Seeds are mainly distributed by water, but they can also be dispersed by animals and humans. Seeds do not drop until the air temperature becomes cold in the early autumn. A single plant can produce over 300,000 seeds.


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