Hoary
cress
Cardaria draba
- Hoary cress (white top) was introduced to the U.S. from Europe late in the 19th century. It was first noted around seaports on the east and west coasts, indicating seed may have been in the soil that was used as ballast for sailing ships. Hoary cress can establish under a wide variety of environmental and climatic conditions. It has become a very serious agricultural weed problem. Idaho has listed hoary cress as a noxious weed.
- Hoary cress is a perennial that develops from stout creeping rootstocks. The stems may grow up to two feet in height, producing grayish-green leaves that are shaped like arrowheads. Numerous small, white flowers are borne on stalks radiating from a stem. The dense flowers cause the weed to have a white, flat-topped appearance. Two small, flat, reddish-brown seeds are contained in each of the heart-shaped seed pods.
- The deep and creeping rootstalks make this weed difficult to control since cultivation tends to spread root pieces that start new plants.
Report
Sightings of Noxious Weeds
Contact:
Kim Pierson, USFS Botanist
208-737-3212
kpierson@fs.fed.us
SPREAD THE WORD ... NOT THE WEEDS
- Drive only on established roads and trails away from weed infested areas.
- When using pack animals, carry only feed that is certified weed free.
- Removed weed seeds from pack animals.
- Don't pick the flowers of noxious weeds and take them home.
- Don't pick and transport wild flowers that you can't identify.
- Don't camp or drive in weed infested areas.
Weed
Removal Instructions
No Flowers or Seed Present:
Pull the weed and leave it on the area.
Flowers
or seed present on the weed:
Pull the weed. Be careful the seed does not fall from the weed. Place
the weed in a plastic bag or similar container.
Dispose of the weed by burning or turn it in at a Ranger Station.