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Hounds tongue

(Cynoglossum officinale)

Photo of hound's tongue
Photo credit: Robert Videki, Doronicum KFT,

An herbaceous biennial that can grow to be 1-4’ tall on a single stem that branches above.


Other names for this plant include:
  • Common names: common hound's tongue, gypsy flower, dog's tongue
  • Scientific names: Cynoglossum officinale L.f. bicolor
Ecological threat:
  • Invades pastures, roadsides, grasslands, riparian areas and meadows.
  • Alkaloids present in the plant decrease in toxicity as it matures, yet it can still be toxic to horses and cattle.
Overview map of hound's tongue classification in WI
Restricted (orange) counties

Classification in Wisconsin: Restricted

Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for hounds tongue was based upon this literature review [PDF] developed by the department.


Leaves: Elliptical, alternate leaves are dark green and slightly hairy. In the rosette stage, leaves are 6-8” long; in the second year, basal leaves are up to 12” long and reduce in size as they progress up the stem.

Flowers: Arranged in panicles in the upper leaf axils, red-purplish flowers bloom from June-July. They are up to 0.3” wide, have 5 petals and are saucer to funnel-shaped.

Fruits & seeds: Each flower produces 4 nutlets, or small nuts, that are covered in barbs. Nutlets that remain on the plant are viable for 2-3 years.

Roots: Large, woody taproot.


Mechanical: Mow second-year plants while in the flowering stage before seed production. Use a sharp shovel to cut 1-2” below the soil surface.

Chemical: Foliar spray rosettes in spring using 2% solutions of picloram, dicamba, or metsulfuron.


View hounds tongue pictures in our photo gallery!


Sources for content:
  • University of Washington - The Burke Museum of Natural History and Culture.
  • Cynoglossum officinale [exit DNR]. Klinkenberg, Brian. (Editor) 2009. E-Flora BC: Electronic Atlas of the Plants of British Columbia []. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 8/21/2009 10:15:40 AM].
Links for more information: