Brassicaceae: annual growing to 0.3 m (1ft). The small white flowers are borne in a corymb on wiry green stems, soon followed by the seeds and often continuing to flower as the first seeds ripen. Blooming from spring to autumn. Seeds burst explosively when touched, sending the seeds flying far from the parent plant. The stems are hairless and the leaves do not clasp the stems. Found on open and cultivated ground, rocks, scree, walls and such. Native to most of the northern Hemisphere, including Britain.
The leaves and flowers can be eaten raw or cooked, they have a hot cress-like flavour, and are mainly used as a garnish or flavouring in salads, but are also sometimes used as a potherb.
The plant germinates most freely in the autumn and so leaves are usually available all winter, but can be sown anytime of the year. Very easy. Plants grows best in damp, recently disturbed soil. These conditions are prevalent in nursery or garden centre plants, and is a common weed in my poly-tunnels, but this is a weed you can eat!