Cardamine pratensis is a herbaceous, hairless, perennial plant growing to 40–60 cm tall, with pinnate leaves 5–12 cm long with 3-15 leaflets, each leaflet about 1 cm long. The flowers are produced on a spike 10–30 cm long, each flower 1–2 cm diameter with four pale pink (rarely white) petals. The style of the fruit is short or longish. It grows best close to water. It is common throughout the British Isles.
It is grown as an ornamental plant in gardens, and has become naturalised in North America as a result of cultivation. In some European countries, including parts of Germany, the plant is now under threat.
It is a food plant for the orange tip butterfly (Anthocharis cardamines); see here, (although shown here with a Large White) and makes a valuable addition to any garden which aims at attracting wildlife. It was once used as a substitute for watercress.
Information based on Wikepaedia.
Photographs taken on 24 May 2014 in Jordanstown (see also photographs of the Orange Tip butterfly taken in Jordanstown 21 April 2011.