Lythrum salicaria

Perennial of the Lythraceae family, the common loosestrife is widely spread in Europe, temperate Asia, and North Africa. It colonizes the edges of watercourses, reed beds, wet meadows, and ditches, always near water or on waterlogged soils, from the plain to the lower montane level.

It forms powerful upright clumps with quadrangular stems, commonly reaching 80 to 120 cm in height, sometimes more in very favorable conditions. The leaves are lanceolate, sessile, opposite or whorled in threes, medium green, slightly hairy. At the end of the season, the foliage takes on orange to reddish hues before disappearing.

The flowers, with six crumpled petals of a bright purple-pink, are arranged in long, dense, tapered terminal spikes that can exceed 30 cm. Their floral structure is remarkable: the species is tristylous, meaning that the flowers exist in three different forms depending on the relative length of the stamens and style, a mechanism promoting cross-pollination. In its natural habitat, its flowering extends from June to September.

Very nectariferous, it is diligently foraged by bees and bumblebees. Introduced in North America, it is considered invasive there. In traditional phytotherapy, its aerial parts were used for their astringent properties. It easily establishes itself on the banks of water bodies, in constantly fresh to moist soil, in the sun or light partial shade.