Bittercress, also known as rocketcress or winter rocket, is a biennial herb belonging to the mustard family. This plant grows to about 30–60 centimetres of height. The stem is ribbed and hairless, branched at the base. It has a basal rosettes of shiny, dark green leaves. The flowers are borne in spring in dense terminal clusters above the foliage. The flowering period extends from about April through July.