[2] Winged loosestrife is an upright, branching herbaceous plant growing to about one metre tall.

The stems are woody in the lower parts of the plant, square in cross section with slightly winged angles.

The flowers are borne singly or in pairs in the axils of the much reduced upper leaves.

[4] Winged loosestrife is found growing in wet meadows and fens, pond and lake margins, beside streams and by railroads.

[7] The Lythrum genus is listed as a noxious weed in Michigan, North Carolina, and Wisconsin.