Water Mint - Mentha aquatica

Variable short to tall plant with a strong aromatic small when crushed, but not as sweetly aromatic as some other mints. Flowers lilac-pink 4 to 6 mm long in a dense oblong head often with 1 or 2 distinct whorls of flowers below.

There are many hybrid and naturalised cultivated varieties of mint, making this a difficult genus 

Flowers in terminal heads, ovate leaves with distinct petioles, calyx tube hairy

Photo of whole plant in flower, including leaves; details of flowers

Any wet or swampy habitat, often with its feet in water.

July to September.

Perennial.

Common throughout Britain except in the Scottish Highlands.

Fairly common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 325 of the 617 tetrads.