Google Translate Disclaimer

A number of pages on the Government of Saskatchewan's website have been professionally translated in French. These translations are identified by a yellow box in the right or left rail that resembles the link below. The home page for French-language content on this site can be found at:

Renseignements en Français

Where an official translation is not available, Google™ Translate can be used. Google™ Translate is a free online language translation service that can translate text and web pages into different languages. Translations are made available to increase access to Government of Saskatchewan content for populations whose first language is not English.

Software-based translations do not approach the fluency of a native speaker or possess the skill of a professional translator. The translation should not be considered exact, and may include incorrect or offensive language. The Government of Saskatchewan does not warrant the accuracy, reliability or timeliness of any information translated by this system. Some files or items cannot be translated, including graphs, photos and other file formats such as portable document formats (PDFs).

Any person or entities that rely on information obtained from the system does so at his or her own risk. Government of Saskatchewan is not responsible for any damage or issues that may possibly result from using translated website content. If you have any questions about Google™ Translate, please visit: Google™ Translate FAQs.

Purple Loosestrife or Fireweed - Which is It?

By Sherri Roberts, PAg, Crops Extension Specialist, Weyburn

June 2022

Purple Loosestrife and Fireweed
Purple loosestrife (L) Fireweed (R)

At first glance, these two plants look very similar, but there is a big difference in their impact on the Saskatchewan environment. Purple loosestrife, originally a horticulture plant, is an invasive weed that prefers moist soil, has invaded wetlands, marshlands and waterways to the point of choking out natural vegetation. Fireweed is a native wildflower that inhabits drier upland areas and is often mistaken for purple loosestrife. This article will cover some of the simple ways to differentiate between these two species.

Purple Loosestrife flowers
Purple loosestrife flowers


Purple loosestrife flowers are attached directly to the stem and will have five to seven reddish-purple to magenta-coloured petals surrounding a small yellow centre.

Fireweed flowers are borne at the end of a long tubular structure with a short stalk and will have four magenta to pink petals and four narrower pink sepals behind the petals. The style will have four stigmas.


Purple loosestrife stems are angular with five or six sides and are hairless to slightly hairy.

Fireweed stems can also be reddish in colour but the stem is smooth and round.


Fireweed leaves
Fireweed leaves

Purple loosestrife leaves are attached opposite from one another and directly to the stem. Lobes at the base wrap past the stem. Veins go all the way to the edge of the leaf.

Fireweed leaves are borne alternately on the stem and do not have basal lobes that go beyond their attachment point. Veins in fireweed leaves loop back in on themselves to create a continuous vein that runs parallel to the margins to the leaf.

We need your feedback to improve Help us improve