Houndstongue

houndstongue seed
houndstongue plant
houndstongue flower

Houndstongue

Cynoglossum officinale

Information Sheet (PDF)


Colorado List B - Control required in Jefferson County

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


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.