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You are here: Home / Plants / Species Profiles / Whitetop
Species Profiles


WhitetopScientific name: Lepidium draba L. Desv. (formerly known as Cardaria draba) (ITIS)

Common names: Whitetop, hoary cress, whiteweed, peppergrass, heart-podded hoarycress, hoary cardaria

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Selected Resources

Native To: Eurasia (Zouhar 2004)

Date of U.S. Introduction: 1800s (Zouhar 2004)

Means of Introduction: Possibly introduced as an ornamental (Zouhar 2004)

Impact: Crowds out native species and reduces crop yields (Zouhar 2004)

Current U.S. Distribution:


Selected Resources:

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Council or Task Force

Invasive Plants of California's Wildlands - Cardaria draba
California Invasive Plant Council.
In online book: Bossard, C.C., J.M. Randall, and M.C. Hoshovsky (Editors). 2000. Invasive Plants of California's Wildlands. University of California Press. Berkeley, CA

Fact Sheet: Hoary Cress (Jan 2014; PDF | 983 KB)
Alberta Invasive Species Council (Canada).
See also: Fact Sheets for more information about individual invasive species, including those listed as "Prohibited Noxious" and "Noxious" under the Alberta Weed Control Act


Federal Noxious Weed Disseminules of the U.S. - Fact Sheet: Cardaria draba
USDA. APHIS. PPQ. Center for Plant Health Science and Technology; California Department of Food and Agriculture.

Invasive Plant Atlas of the United States - Hoary Cress
University of Georgia. Center for Invasive Species and Ecosystem Health.

Hoary Cress Consortium
University of Idaho.

Invasive Species Compendium - Lepidium draba
CAB International.

TISI Inventory - Whitetop / Hoary Cress
Texas State University System. Texas Invasive Species Institute.

Federal Government

U.S. National Plant Germplasm System - Lepidium draba
USDA. ARS. National Genetic Resources Program. GRIN-Global.

Fire Effects Information System (FEIS) - Cardaria spp.
USDA. FS. Rocky Mountain Research Station. Fire Sciences Laboratory.

PLANTS Database - Whitetop
USDA. NRCS. National Plant Data Center.

International Government

Weeds in Australia - Hoary Cress (Lepidium draba)
Australian Government. Department of the Environment and Energy.

State Government

Encycloweedia: Data Sheet - Lepidium genus
California Department of Food and Agriculture.
See also: Included on California's noxious weed list; see Encycloweedia: Program Details for additional resources

Noxious Weed Species - Hoary Cress
Colorado Department of Agriculture. Conservation Services Division. Noxious Weed Program.

Class C Noxious Weed: Hoary Cress
Washington State Noxious Weed Control Board.

Hoary Cress Whitetop: Options for Control (PDF | 1.04 MB)
Lincoln County Noxious Weed Control Board (Washington).

See also: Weed I.D. and Options for Control for more species


Weed Control in Natural Areas in the Western United States: Hoary Cress (Whitetop), Lens-Podded and Hairy Whitetop (2013; PDF | 252 KB)
University of California. Weed Research and Information Center.
See also: Weeds in Natural Areas for more information sheets

Biology, Ecology, and Management of Whitetop (Cardaria spp.) (2011)
Montana State University Extension.


Noxious Weed Information - Hoary Cress (Whitetop)
Colorado Weed Management Association.

Weed Identification - Hoary Cress (Whitetop)
Montana Weed Control Association.


Integrated Taxonomic Information System. Lepidium draba. [Accessed Sep 10, 2014].

Zouhar, K. 2004. Cardaria spp. In: Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.

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Last Modified: Sep 15, 2018
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