Surprise Field Office

Noxious Weeds

Hoary Cress (Cardaria draba) 
Mustard Family (Brassicaceae)

Photo of Hoary Cress

Description:  Deep rooted perennial to 3 feet. Leaves blue-green, lance-shaped. Lower leaves stalked, while upper leaves with two lobes clasping the stem. Many clusters of white flowers give a white, flat-topped appearance. Flower with 4 petals. Seed capsules heart-shaped, containing 2 reddish-brown seeds separated by a narrow, papery partition. Reproduces from both root segments and seed.

Habitat:  Native to Europe. Commonly grows in distrubed sites, saline soils, and along river banks and other waterways. Highly competitive once established, easily displacing native vegetation and forming a monoculture. Mechanical removal is strongly discouaged as all small, broken segments left behind will form a new plant that will produce many more plants.

Distribution:  Hoary cress, sometimes called Whitetop (Cardaria pubescens), is generally found throughout northeastern California, especially in Big Valley (Lassen County and Modoc County), Madelaine Plains (Lassen County), Tulelake (Modoc County and Siskiyou County), and in the Montague area (Siskiyou County).

Flowering Period:  April to July.

Glossary of Plant Terms

Next Plant