Cynoglossum officinale

Keys to Identification

• A biennial that was introduced from Europe
• Reproduces by seeds
• Stem is erect, stout, heavy, 1-1/2 to 3 ft tall
• Fowers are terminal and reddish-purple
• Seeds about 1/3 in long, the outer surface covered with short barbed prickles
• Contains alkaloids that may cause liver cells to stop reproducing

This information courtesy of the Colorado Natural Areas Program

Family

Boraginaceae (Borage)

Other Names

Hound’s tongue, dog bur, gypsy flower

USDA Code

CYOF

Legal Status

Colorado Noxious Weed List B

Identification

Lifecycle

Biennial or short-lived perennial

Growth form

Forb

Flower

Flowers are reddish-purple, with five petals, arranged in panicles in the upper leaf axils.

Seeds/Fruit

The fruit is composed of four prickly nutlets each about 1/3 in long (Whitson et al. 1996)

Leaves

Leaves are alternate, 1-12 in long, 1-3 in wide, rough, hairy, and lacking teeth or lobes (Whitson et al. 1996). Basal leaves are elliptical to oblanceolate and tapered at the base.

Stems

Houndstongue produces a single flowering stem. The stem is erect, stout, heavy, 1 1/2-3 ft tall and usually branched above.

Roots

Houndstongue has a thick, black, woody taproot.

Seedling

Houndstongue forms a rosette the first year of its life cycle.

Similar Species

Exotics

None known.

Natives

None known.

Impacts

Agricultural

Houndstongue contains toxic alkaloids that stop liver cells from reproducing. Therefore, houndstongue reduces livestock and wildlife forage and grazing animals should be kept away from houndstongue infested areas. Animals may live six or more months after eating a lethal dose of houndstongue. Sheep are more resistant to houndstongue poisoning that cattle or horses. The burs may reduce the value of wool.

Ecological

Houndstongue is an early sucessional species on recently disturbed sites.

Human

Due to its toxicity to grazing animals, houndstongue should not be eaten by humans.

Habitat and Distribution

General requirements

Houndstongue prefers areas with more than 10% bare ground (Butterfield et al. 1996), and is common on gravelly, alkaline soils (Stubbendieck et al. 1995).

Distribution

Houndstongue is found over much of North America. It grows on rangeland, pastures, abandoned cropland, roadsides, and waste places (Butterfield et al. 1996). Houndstongue is found on rangeland, pastures, and roadsides throughout Colorado up to about 9000 feet.

Historical

Houndstongue is a native of Eurasia that was introduced to North America as a contaminant in agricultural seed.

Biology/Ecology

Life cycle

Houndstongue is a biennial that produces a rosette the first year. During the second year a flowering stem bolts and produces fruit.

Mode of reproduction

Seed.

Seed production

Mature plants can produce up to 2,000 seeds (Butterfield et al. 1996).

Seed bank

Seeds remaining on the parent plant may remain viable for 2-3 years. Buried seed rarely survive more than one year (Butterfield et al. 1996).

Dispersal

Seeds stick to clothing and animals and have the ability to be spread great distances.

References

Butterfield, C., J. Stubbendieck, and J. Stumpf. 1996. Species abstracts of highly disruptive exotic plants. Jamestown, ND: Northern Prairie Wildlife Research Center Home Page. http://www.npwrc.usgs.gov/resource/othrdata/exoticab/exoticab.htm (Version 16JUL97).

Stubbendieck, J., G.Y. Friisoe and M.R. Bolick. 1995. Houndstongue. Weeds of Nebraska and the Great Plains. Nebraska Department of Agriculture, Bureau of Plant Industry, Lincoln, Nebraska. pg. 185.

Whitson, T.D.(ed.), L.C. Burrill, S.A. Dewey, D.W. Cudney, B.E. Nelson, R.D. Lee, R. Parker. 1996. Houndstongue. Weeds of the West. Western Society of Weed Science, in cooperation with the Western United States Land Grant Universities Cooperative Extension Services, Newark CA. pg. 202.