Houndstongue

Cynoglossum officinale

Houndstongue

Family: Boraginaceae

Other Common Names: gypsy flower
Weed class: B
Year Listed: 1988
Native to: Europe and Asia
Is this Weed Toxic?:

humans, livestock

Why Is It a Noxious Weed?

It is a very strong competitor of desirable forage and is poisonous. It contains pyrrolizidine alkaloids that stop the reproduction of liver cells. Sheep are less susceptible than cattle or horses. It can also cause dermatitis in humans.

How would I identify it?

General Description

Houndstongue is a biennial or short-lived perennial that grows 1 to 4 feet tall. The taproot is thick, woody, black and branching. All parts are covered with hairs.

Flower Description

Flower clusters in upper leaf axils and at stem ends. Flowers are a dull reddish-purple to burgundy and 3/8 inch wide. They have 5 lobes.

Leaf description

Leaves are alternate, hairy, rough and lacking teeth or lobes. Lower leaves are narrow, 4 to 12 inches long and about 1 to 2 inches wide and have petioles (leaf stalks). Upper leaves are similar and without petioles (attach directly to the stem).

Stem description

Stems are upright and branching at the ends. They are hairy and coarse.

Fruit Seed Description

Flowers form 4 nutlets, with each nutlet containing one seed. Nutlet surface is covered with barbed hooks that allow itself to be attached to animals and people for dispersal.

Where does it grow?

Houndstongue is found on roadsides, meadows and in disturbed areas. It is also shade tolerant and thrives in wetter grasslands. Please click here to see a county level distribution map of houndstongue in Washington.

How Does it Reproduce?

Houndstongue reproduces by seed and is self pollinating. Seed production varies from about 314 to 674 seeds per plant. Seeds remaining on the soil surface can remain viable up to two years.

How Do I Control It?

Mechanical Control

Clip and properly discard flowering stems to greatly reduce seed production.

Cultural Control

Cultivation of young rosettes, in the autumn or early spring, provides effective control. Re-seed problem areas with fast growing grasses. Do not overgraze.

Biological Control

Herbicide Control

Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

For More Information

See our postcard for early detection information about houndstongue.

See our Written Findings for more information about houndstongue (Cynoglossum officinale)

Lincoln County NWCB Fact Sheet on houndstongue

Franklin County NWCB Fact Sheet on houndstongue

King County NWCB Fact Sheet on houndstongue

Additional Photos