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Plant Conservation Alliance®s Alien Plant Working Group 

Xeeds HoneXild: Alien Plant Invaders of Natural Areas 

http://www.nps.gov/plants/alien/

FACT SHEET: ANNUAL BASTARD-CABBAGE

Annual Bastard-Cabbage 

Rapistrum rugosum (L.) All. 

Mustard family (Brassicaceae) 

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. 

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. 
20 May 2005 Page 2 of 3 

Plant Conservation Alliance®s Alien Plant Working Group 

Xeeds HoneXild: Alien Plant Invaders of Natural Areas 

http://www.nps.gov/plants/alien/

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. 

USE PESTICIDES WISELY: Always read the entire pesticide label carefully, follow all mixing and application instructions and wear all 

recommended personal protective gear and clothing. Contact your state department of agriculture for any additional pesticide use 

requirements, restrictions or recommendations. 

NOTICE: mention of pesticide products on this page does not constitute endorsement of any material.

CONTACT 

For more information on the management of annual bastard-cabbage, please contact: 

• Steve Windhager, Ph. D., Lady Bird Johnson Wildflower Center, Austin, TX, stevew@wildflower.org 

• Mark Simmons, Lady Bird Johnson Wildflower Center, Austin, TX, msimmons@wildflower.org 

AUTHOR 

Karen Enyedy, Freelance Writer/Editor, Austin, TX 

EDITOR

Jil M. Swearingen, National Park Service, Washington, DC 

REVIEWERS

Mark Simmons and Dr. Steve Windhager, Lady Bird Johnson Wildflower Center, Austin, TX 

PHOTOGRAPHS 

Mark Simmons, Lady Bird Johnson Wildflower Center, Austin, TX 

REFERENCES 

Diggs, Jr., G. M., Lipscomb, B.L., and O'Kennon, R. J. Shinners and Mahler's Illustrated Flora of North Central Texas. Fort 

Worth, TX: Botanical Research Institute; 1999; p. 476. 

Hashem, A., Bowran, D., Piper, T. and Dhammu, H. 2001. Resistance of wild radish (Raphanus raphanistrum) to 

acetolacetate synthase-inhibiting herbicides in the Western Australia wheat belt. Weed Technology 15:68-74. 

Kartesz, J.T. and C.A. Meacham. 1999. Synthesis of the North American Flora. North Carolina Botanical Garden, 

University of North Carolina at Chapel Hill. Chapel Hill, NC. [CD] 

Lemke, David E. and Worthington, Richard D. Brassica and Rapistrum (Brassicaceae) in Texas. The Southwestern 

Naturalist; June, 1991: pp. 194-196. 

Neiman, Bill*. Personal conversation 4/9/2000. *President, Native American Seed. 

Rollins, Reed C. The Cruciferae of Continental North America. Stanford, CA: Stanford University Press; 1993; p. 722. 

Swearingen, J. 2009. WeedUS Database of Plants Invading Natural Areas in the United States: Annual Bastard-Cabbage 

(Rapistrum rugosum). http://www.invasive.org/weedus/subject.html?sub=14105. 
20 May 2005 Page 3 of 3 

Plant Conservation Alliance®s Alien Plant Working Group 

Xeeds HoneXild: Alien Plant Invaders of Natural Areas 

http://www.nps.gov/plants/alien/

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN). [Online 

Database] National Germplasm Resources Laboratory, Beltsville, Maryland. (http://www.arsgrin.gov/var/apache/cgi-bin/npgs/html) 

USDA, NRCS. 2009. The PLANTS Database (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 

70874-4490 USA.