This is a perennial wildflower which grows on waste ground, laneways and roadsides. It carries heads of small bright, yellow, 4-petalled flowers (7-9mm across) from May to July on ridged stalks reaching 85-90cm high. Its dark green leaves are shiny, pinnately lobed with the end lobe being longer and wider than the others. The seedpods are long (15-30mm) and stiffly erect. This is a native plant belonging to the Brassicaceae family.
I found this little plant on a wet walk through a pine forest near Laragh, Co Wicklow in 2008 and I photographed it at that time.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre