Weed Seed: Barbarea spp. (Yellow rocket)

Family

Brassicaceae

Synonym

Winter cress

Common Name

Yellow rocket

Regulation

Secondary Noxious, Class 3 in the Canadian Weed Seeds Order, 2016 under the Seeds Act.

Distribution

Canadian: The genus includes 4 species found in Canada, distributed across all provinces and territories (Brouillet et al. 2016Footnote 1). The native species B. orthoceras occurs across Canada except NS, while the introduced species occur as follows: B. stricta in ON and QC; B. verna in BC and NF, and; B. vulgaris in all provinces but not the territories.

Worldwide:The genus contains about 20 species with the majority distributed in the temperate regions of Eurasia and North America, and a few species in subtropical regions of East Asia and Australia (Agerbirk et al. 2003Footnote 2). The type species, B. vulgaris, has a wide native distribution area in Eurasia, and is introduced as a noxious weed in North America, Africa, Australia and New Zealand (MacDonald and Cavers 1991Footnote 3, Agerbirk et al. 2003Footnote 2).

Duration of life cycle

Biennial to short-lived perennial

Seed or fruit type

Seed

Identification features

Size

  • Seeds of Barbarea spp. are medium-sized within the Brassicaceae; similar size as Brassica species
  • Barbarea spp. seed length varies from 1.3 - 2.0 mm

Shape

  • Barbarea spp. seeds are oval or oblong; strongly compressed

Surface Texture

  • Barbarea spp. seed surface is reticulate with deep cells; obscured by shining, yellowish film

Colour

  • Barbarea spp. seeds surface black; appears grey-brown due to obscuring film

Other Features

  • Hilum of Barbarea spp. is in a notch at one end of the seed
  • A furrow extends part of the way along the seed, separating cotyledons from the radicle

Habitat and Crop Association

Cultivated fields, gardens, pastures, meadows, old fields, shores and swamps, roadsides and disturbed areas (Darbyshire 2003Footnote 4). B. vulgaris is an important weed of small-seeded grain and hay crops in Canada, legume-grass meadows in the U.S., and vegetable and fruit crops in Europe (MacDonald and Cavers 1991Footnote 3).

General Information

Yellow rocket produces abundant seed early in the growing season and behaves as an early spring dominant. Seeds may be spread as contaminants in seed lots of timothy and other similar sized grains; they may also be spread in hay and manure, and have been shown to remain viable after passing through a variety of animals.

Individual plants may produce up to 88,000 seeds per plant, and seeds may remain dormant in the soil for 10-20 years. It can also reproduce vegetatively from the roots and rosettes (MacDonald and Cavers 1991Footnote 3).

Similar species

Distinguishing Barbarea spp. from other Brassicaceae

Seeds of Barbarea spp. can be distinguished from Brassicaceae genera with a similar oblong shape, furrow and surface reticulations such as: Descurainia spp. and Sisymbrium spp. by:

  • Dark grey-brown colour
  • Surface reticulation with deep cells
  • Shining, yellowish film on the surface

Photos

Early yellow rocket (winter cress) (Barbarea verna) seeds
Early yellow rocket (winter cress) (Barbarea verna) seed
Early yellow rocket (winter cress) (Barbarea vulgaris) seeds
Early yellow rocket (winter cress) (Barbarea vulgaris) seed
Early yellow rocket (winter cress) (Barbarea vulgaris) seed, side view
Early yellow rocket (winter cress) (Barbarea vulgaris) seed