Also known as Mismín dearg, this is a stiff, hairy, upright perennial which has the familiar smell of mint. It grows in damp ground and wet places where you'd normally wear wellies and it reaches up to about 90cm tall. The globular heads of lilac-blue flowers (3-4mm long) are held in whorls along the square stems with two opposite leaves beneath each whorl, the stem bearing a terminal head of these flowers. Each four-lobed flower has four protruding stamens. The leaves are oval and toothed and the plant often is tinged reddish. This plant, blooming from July to September, is much visited by butterflies such as the Small Tortoiseshell and the Peacock. This is a native plant which belongs to the family Lamiaceae.
My first record of this wildflower is in Derrynane, Co Kerry in 1977 and I photographed it on the Grand Canal at Vicarstown, Co Kildare in 2003.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre