Hound's Tongue (Cynoglossum officinale L.)

A taprooted, leafy plant growing to 1.2m tall. Blooms from June to September. Flowers are arranged in a line along upper stems and are small, reddish-purple, and have five petals. Seeds are carried in small nutlets covered in barbed prickles that easily attach to animals and clothing.


Habitat and Ecology

Hound’s-tongue is a weed in low- to mid-elevation grasslands and forests, mainly associated with disturbed sites such as roadsides and clearcuts. It has adapted to alkaline soils.


Hound’s-tongue is poisonous to livestock (sometimes lethal), particularly cattle and horses. Invasions of hound’s-tongue in hay fields reduce available forage for livestock. Seed pods cling to the fur of animals, causing stress to animals and sometimes requiring veterinarian services for removal.


Biocontrol released in the 1990s appears to be successful. Plants may be killed by mowing before seed-set. Young plants can be hand pulled; older plants require shovels to dig out as much of the root as possible. Seeds should be removed from animals and humans when moving out of an infested area. Please contact LRISS for all other treatment information.


Province of British Columbia. 2002. Guide to Weeds in British Columbia.


Parish, R., Coupe, R., & Lloyd, D. 1996. Plants of Southern Interior British Columbia and the Inland Northwest.

Photo reference: Mary Ellen (Mel) Harte, Bugwood.org