This is a little perennial or biennial plant which can be easily overlooked. In many ways it is very like its annual relative, Hairy Bitter-cress, but it can be distinguished by a few identifying factors; firstly it's taller than its cousin, reaching to 50cm high; then there are the leaves – this plant has between 4 and 10 stem leaves as well as its basal rosette whereas Hairy Bitter-cress only has 1 – 4 stem leaves and a basal rosette. The leaves are pinnately divided and have ovate, rounded lobes. The stems of this plant are – as the common name suggests – wavy, and they are also quite hairy. However what I find to be the simplest way of differentiating these two little wildflowers is by counting the number of stamens – Wavy Bitter-cress has 6 stamens and Hairy Bitter-cress has only 4. These emerge from pretty little white 4-petalled flowers (3-4mm across) which are borne in loose clusters on the hairy, wavy, grooved stems from March to September. The seeds are held in long, narrow seed-pods which barely reach above the flowers. This is a native plant which grows on waste ground, mostly damp and shady, and it belongs to the Brassicaceae family.
I first recorded this little wildflower growing in Inishtioge, Co Kilkenny in 2009 and I photographed it there at that time.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre