Text Size:   A+ A- A   •   Text Only
Find     
Site Image
houndstongue (Cynoglossum officinale)
ODA rating: B
 
USDA Symbol: CYOF
Oregon houndstongue distribution
 
Other common names
Hounds tongue, gypsy flower, rats and mice, dog bur
 
Click on photo to view larger image
 
 
Photo by Rich Old, XID Services
 
 
Photo by Rich Old, XID Services

 
 
 
 
Photo by Tom Forney, Oregon Department of Agriculture
 
If images are downloaded and used from the ODA web site please be sure to credit the photographer.
 
Description
Biennial; blooms June to August. Grows 1 to 4 ft tall; forms rosette first year and sends up flowering stalk second year. Leaves alternate, rough, hairy (resembling a hound’s tongue) and 1 to 12 inches long. Flowers reddish purple and terminal. Seeds nutlets.
 
Impacts
Houndstongue can be a serious problem in rangeland and pasture. The weed is highly invasive and can significantly reduce forage. The plant produces barbed seeds, or burrs, which allow the plant to readily adhere to hair, wool, and fur and can in turn reduce the value of sheep wool.  In addition houndstongue contains large quantities of pyrrolizidine alkaloids which are toxic to cattle and horses.
 
Known hazards
Houndstongue is toxic, containing pyrrolizidine alkaloids, causing liver cells to stop reproducing. Animals may survive six months or longer after they have consumed a lethal amount. Sheep are more resistant than cattle or horses.
 
Introduction
This plant was introduced to North America as a contaminant of cereal seed in the late 1800s
 
Distribution in Oregon

Biological controls
No approved biological control agent is currently available. However, research is being conducted on five promising insects: a root weevil, a stem weevil, a seed weevil, a root beetle and a root fly.