Photographic List Complete List Annual bastard-cabbage Amur corktree Asiatic colubrina Asiatic sand sedge Australian pine Black locust Black swallow-wort Burma reed Bush honeysuckles (exotic) Canada thistle Carrotwood Chinaberry Chinese lespedeza Chinese wisteria Climbing euonymus Cogon grass Common buckthorn Common mullein Common reed English ivy Eurasian watermilfoil Fig buttercup Fire tree Fiveleaf akebia Fountain grass Garlic mustard Goutweed Giant reed Japanese barberry Japanese hop Japanese honeysuckle Japanese knotweed Japanese spiraea Japanese stiltgrass Japanese wisteria Kudzu Leafy spurge Melaleuca Mile-a-minute Multiflora rose Musk thistle Oriental bittersweet Pale swallow-wort Paper mulberry Perennial pepperweed Porcelainberry Princess tree Purple loosestrife Russian-olive Salt cedar Siberian elm Silk tree Smooth cordgrass Spotted knapweed Strawberry guava Tall fescue Tree-of-heaven Velvet tree West Indian marsh grass White poplar Wineberry Yellow Himalayan raspberry Yellow starthistle Aquatics Eurasian watermilfoil Herbaceous Plants Annual bastard-cabbage Asiatic sand sedge Burma reed Canada thistle Cogon grass Chinese lespedeza Common mullein Common reed Eurasian watermilfoil Fig buttercup Fountain grass Garlic mustard Goutweed Giant reed Japanese knotweed Japanese stiltgrass Leafy spurge Musk thistle Perennial pepperweed Purple loosestrife Smooth cordgrass Spotted knapweed Tall fescue West Indian marsh grass Yellow starthistle Shrubs Asiatic colubrina Bush honeysuckles (exotic) Common buckthorn Fire tree Japanese barberry Japanese spiraea Multiflora rose Russian-olive Silk tree Strawberry guava Wineberry Yellow Himalayan raspberry Trees Amur corktree Australian pine Black locust Carrotwood Chinaberry Common buckthorn Melaleuca Paper mulberry Princess tree Salt cedar Siberian elm Silk tree Strawberry guava Tree-of-heaven Velvet tree White poplar Vines Black swallow-wort Chinese wisteria Climbing euonymus English ivy Fiveleaf akebia Japanese honeysuckle Japanese hop Japanese wisteria Kudzu Mile-a-minute Oriental bittersweet Pale swallow-wort Porcelainberry

Rapistrum rugosum (L.) All.
Mustard family (Brassicaceae)
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NATIVE RANGE
Central Europe, the Mediterranean, northern Africa and western, temperate Asia

DESCRIPTION
Annual bastard-cabbage is an annual, many-branched, herbaceous plant that grows from 1 to 5 feet or more in height and has a taproot that can become quite large. Leaves are deep green, lobed and wrinkled, and sometimes have a reddish cast. The terminal lobe is larger than the lateral lobes, especially on the basal leaves. Younger leaves growing higher up on the plant are less lobed and more elongated. Annual bastard-cabbage typically flowers from early spring into summer, bearing clusters of small, showy yellow flowers at the tips of its branches, resembling those of broccoli and cabbage. Annual bastard-cabbage can be identified more easily and certainly by its unusually shaped fruit - a two-segmented seed capsule, called a silique. The seed capsule is stalked, with a long beak at the tip, and contains 1-2 seeds. The seeds are oval-shaped, dark brown, smooth, and tiny (about 1/16-inch).

Two subspecies of this plant are recognized: R. rugosum ssp. rugosum and R. rugosum ssp. orientale. Annual bastard cabbage is also known as turnip-weed, common giant mustard, ball mustard, wild turnip, wild rape and tall mustard-weed. It is designated a terrestrial noxious-weed seed in the state of Texas.

ECOLOGICAL THREAT
Annual bastard-cabbage is an early successional plant that develops a broad, robust mass of basal leaves, which allows it to successfully outcompete native plant species. In some places, it forms a monoculture (a vegetative cover of mostly one species). Annual bastard-cabbage has long been established on agricultural fields, roadsides, and disturbed lands and is becoming invasive in natural areas such as open forests and along streams. 

DISTRIBUTION IN THE UNITED STATES
Annual bastard-cabbage is documented to occur in sixteen states, from California to New England. Click here to see a distribution map.

HABITAT IN THE UNITED STATES
Annual bastard-cabbage grows mostly in open sites on disturbed soils.

BACKGROUND
The history of introduction of annual bastard-cabbage into the U.S. is uncertain. It appears to be spreading through contaminated grass seed mixes or mulching materials. Because its seeds are similar in size to those of wheat and rye, weed seed screens may fail to remove it from grass seed mixes. 

BIOLOGY & SPREAD
Annual bastard-cabbage seeds germinate early in the growing season (late fall or early winter) and quickly cover the ground with a blanket of leafy rosettes (circles of leaves at ground level). These dense rosettes block sunlight from reaching seeds and seedlings of native plants.

MANAGEMENT OPTIONS
Manual removal of the plant and its taproot, and disposal of seeds, is effective, though labor-intensive. Research is now underway at the Lady Bird Johnson Wildflower Center to determine if oversowing with native grasses and herbaceous groundcovers is effective in controlling annual bastard-cabbage.

Chemical
Chemical control of annual bastard-cabbage may be difficult because of its ability to ability to attain resistance to several selective herbicides. Research into effective herbicide control is on-going.