Houndstongue

Houndstongue

Cynoglossum officinale

Colorado List B 

Information Sheet (PDF)

Eradication Zone Map (pdf)

General

• Biennial (short-lived perennial)
• Contains alkaloids that are poisonous to livestock
• Family: Boraginaceae
• Native to Eurasia
• Rosettes form the first year and bolt early in May to June of the next year

Habitat

• Disturbed areas, pastures, rangelands, roadsides and right-of-ways up to 9,000 feet elevation

Plant

Vegetation

• Leaves are hairy, 1 1/2 inches long and 1 to 3 inches wide
• Mature plants are 1 1/2 to 3 feet tall

Roots

• Black, woody taproot

Flower

• Color: reddish-purple
• Season: May through July
• Size: 1/4 to 1/2 inch wide
• Produces up to 2,000 seeds

Seed

• Seeds left on the plant may remain viable for 2 to 3 years

Seedling

• Rosettes form the first year

Reproduction

• Seed

Control

Biological

• None

Chemical

• View Information Sheet (PDF)

Cultural

• Prevention – maintain health of site
• Removal

Mechanical

• Burning - N/A
• Grazing - Should not be grazed because it is poisonous to livestock
• Mowing - Second-year plant before seed production

Use all chemicals according to the manufacturer's label. No specific recommendation or endorsement is made or implied by listing methods or products.