This beautiful little plant is probably the bane of most gardeners. It goes by the guise of many common name including Hairy Bittercress, Spring Cress and Hoary Bittercress. It is a plant belonging to the mustard family Brassicaceae. The leaves form a tight rosette of 2 to 6 pairs of rounded leaflets with a larger terminal leaf. The delicate white flowers of 4 petals will only open in bright weather. The hairy leaves have a peppery taste to them and smell like Cress. The long and slender seedpods explode when ripe enough, jettisoning the seeds to new ground. It grows up to 10-20 cm in height.
It flowers for most of the year and is particularly abundant, found growing on all types of bare ground, including in the cracks of walls, paving, roof tiles, in woodland and along the banks of streams.