Ontario Wildflowers website

Purple Loosestrife
Lythrum salicaria

Other common names: Spiked Loosestrife

Family: Loosestrife Family (Lythraceae)

Group: Loosestrifes

Distinctive features: Showy purple flowers. Wetlands. Somewhat four-sided stem.

Similar species:
  •   Purple Loosestrife (a different one)(Lythrum virgatum) - very similar (hence the same Common Name).

Flowers: Summer;  Blue/Violet;  5 parts (petals);  Purple. Many, arranged in a spike. Summer.

Leaves: Grow in pairs or sometimes whorls of three.

Stem: Somewhat four-sided.

Fruit/Seeds: Plentiful.

Habitat: Wet Areas;  Wetlands.

Books: Newcomb's Wildflower Guide: 351    Peterson's Field Guide to Wildflowers: 224, 288    ROM Field Guide to Wildflowers of Ontario: 304   

Native/Non-native: Non-native

Notes: Purple Loosestrife is the infamous invasive alien plant that is taking over some of our wetlands. If found, control measures should be taken to prevent its spread.

Photographs: 84 photographs available, of which 7 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Purple Loosestrife (Lythrum salicaria)

Spike of flowers. They're very pretty.

Purple Loosestrife (Lythrum salicaria)

The start of the invasion. Left unchecked, this wetland by the stream could become a mass of purple flowers, to the exclusion of native flora.

Purple Loosestrife (Lythrum salicaria)


Purple Loosestrife (Lythrum salicaria)

Closeup of one flower.

Purple Loosestrife (Lythrum salicaria)

The top of the flower spike.

Purple Loosestrife (Lythrum salicaria)

Purple Loosestrife (Lythrum salicaria)

Purple Loosestrife in winter.

Range map for Purple Loosestrife (Lythrum salicaria)

PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.

(Range map provided courtesy of the USDA website and is displayed here in accordance with their Policies)