©Mark Hamblin/2020VISION


Scientific name: Lythrum salicaria
A tall plant, purple-loosestrife can form dense stands of bright purple flower spikes in wet habitats like reedbeds, fens and marshes.

Species information


Height: up to 1.5m

Conservation status


When to see

June to August


Purple-loosestrife can be found in wet habitats, such as reedbeds, fens, marshes and riverbanks, where its impressive spikes of magenta flowers rise up among the grasses. Many tall stems can grow from a single root stock. It flowers between June and August, when its nectar becomes a valuable food source for long-tongued insects, such as brimstone butterflies, red-tailed bumblebees and elephant hawk-moths.

How to identify

Purple-loosestrife is a tall plant, with large, pink flower spikes and long green leaves in opposite pairs up the stem.


Found throughout the UK, but less common in Scotland.

Did you know?

Introduced into North America in the 19th century, purple-loosestrife is now an invasive weed, forming impenetrable stands that are unsuitable as cover for native animals and shade out native plants.