Bittercress, herb barbara, yellow rocket
This plant grows to about 30–60 centimetres (12–24 in) of height, with a maximum of 1 metre (3 ft 3 in). The stem is ribbed and hairless, branched at the base. It has a basal rosettes of shiny, dark green leaves. The basal leaves are stalked and lyre-pinnatifid, that is with a large terminal lobe and smaller lower lobes. The cauline leaves are smaller, ovate, toothed or lobed. The flowers are borne in spring in dense terminal clusters above the foliage. They are 7–9 millimetres (0.28–0.35 in) long, with four bright yellow petals.The flowering period extends from about April through July. The fruit is a pod of about 15–30 millimetres (0.59–1.18 in).