|
Houndstongue Cynoglossum officinale |
|||||||||||
|
Keys to Identification:
|
|||||||||||
|
|
|
|||||||||||
|
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 inch long (Whitson et al. 1996) Leaves: Leaves are alternate, 1-12 inches long, 1-3 inches 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, 1.5 to 3 feet high 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: reproduces solely by 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. Integrated Management Summary Houndstongue is poor competitor with native perennials and requires disturbed or bare areas to establish. Once established, houndstongue quickly forms dense monocultures. Treat first year plants with herbicides. Mow bolted plants to eliminate seed production. Repeat this process for several years to exhaust the seed bank. It is imperative to establish a healthy population of native perennials on treated areas to prevent the re-establishment of houndstongue or other noxious weeds. CONTROL References
|
||||||||||||
