Barbarea vulgaris, also called wintercress (usual common name), or alternatively winter rocket, rocketcress, yellow rocketcress, yellow rocket, wound rocket, herb barbara, creases, or creasy greens, is a biennial herb of the genus Barbarea, belonging to the family Brassicaceae.

The plant grows to 80 cm (31 in) high and 25 cm (10 in) wide. The stem is ribbed and hairless, branched at the base. It has 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 mm (1⁄4–3⁄8 in) long, with four bright yellow petals. The flowering period extends from about April through July. The fruit is a pod around 15–30 mm (5⁄8–1+1⁄8 in).

Chemical substances in this species include saponins, flavonoids, and glucosinolates. It usually has a peppery taste.

Formally, B. vulgaris was first published and described by William Aiton in his Hortus Kewensis (1812). Some references still mention Robert Brown as the author. Indeed, botanists believe that Brown was the actual author of the first botanical description of B. vulgaris in the description of the family Brassicaceae. However, W. T. Aiton, the publishing author, did not mention or indicate Brown's name for Brassicaceae; therefore, W. T. Aiton is author of the Brassicaceae novelties in this work.

B. vulgaris has various common names of which the most commonly used is 'wintercress', which can also be used for the entire genus Barbarea. Many other common names are listed in various sources, including (in alphabetical order), 'creases', 'creasy greens', 'cressy-greens', 'English wintercress', 'herb-Barbaras', 'rocket cress', and 'yellow rocket'. Two additional names sometimes used, 'bittercress' and 'upland cress' are ambiguous; the name 'bittercress' usually signifies various species of the genus Cardamine, and 'upland cress' usually signifies B. verna.

The genus name Barbarea derives from Saint Barbara, the patron saint of artillerymen and miners, as this plant in the past was used to soothe the wounds caused by explosions. The species Latin name vulgaris means "common".

Native to Eurasia and North Africa, it is naturalised in many parts of North America and New Zealand as a weed.

It is found in temperate North Africa within Algeria and Tunisia. Also in Asia, within Afghanistan, Armenia, Azerbaijan, the Caucasus, China (in the provinces of Heilongjiang, Jiangsu, Jilin and Xinjiang), Georgia, Iran, Iraq, Japan (in the provinces Hokkaido, Honshu, Kyushu, Ryukyu Islands and Shikoku), Kazakhstan, Kyrgyzstan, Mongolia, Siberia, Tajikistan, Turkmenistan and Turkey. It is also found in tropical parts of Asia, such as India (- in the provinces of Sikkim, Himachal Pradesh, Jammu and Kashmir, Tamil Nadu, Uttar Pradesh and Arunachal Pradesh), Pakistan and Sri Lanka.