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


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


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.

Invasive Species Compendium - Lepidium draba
CAB International.


Hoary Cress Consortium
USDA. ARS. Northern Plains Agricultural Research Laboratory.

Germplasm Resources Information Network (GRIN) - Lepidium draba
USDA. ARS. National Genetic Resources Program.

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.

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


Encycloweedia: Data Sheet - Lepidium genus
California Department of Food and Agriculture.
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 (Written Findings)
Washington State Noxious Weed Control Board.

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


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.


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

Species Fact Sheet: Whitetop (2009; PDF | 377 KB)
Learning Center of the American Southwest.

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: May 18, 2016
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