Noxious Weed Of The Month: Houndstongue
 | Author:
Allison Kosto, MSU Broadwater County Extension Agent
MSU Broadwater County Extension Agent |
Noxious Weed of the Month: Houndstongue
Allison Kosto
MSU Broadwater County Extension Agent
Have you ever gone on a hike or camping trip with your dog and he returns covered in burs? Even though we have several plants with burs in Montana, a likely culprit is houndstongue, also known as beggar’s lice. It’s a Montana Noxious Weed and very prevalent throughout the county, especially in the mountains.
Description & Habitat
Houndstongue is native to Europe and was introduced to North America as an impurity in a cereal grain shipment. It has been reported in at least 41 Montana counties and is listed as a noxious weed in seven western states. It can be found in rangeland, pastures, roadsides, woodlands and distributed areas.
Houndstongue is a biennial (life cycle of two years). The first and second-year growth look vastly different. During the first year it forms a low growing rosette with large leaves that have fine white hairs and veins like a dog’s tongue. The second year it produces a stem, flower and seeds. The stem can reach up to four feet tall and flowers are small reddish-purple. The seeds are pear-shaped and covered with barbs. The plant reproduces solely by seed which can hitch a ride on pets, clothing, livestock and wildlife.
Houndstongue contains alkaloids that are toxic to animals. However, the plants are not very palatable and livestock generally avoid them. There is a greater risk to houndstone poisoning in contaminated hay. It can also displace desirable plants reducing forage quality and quantity and decreasing biodiversity. The burs can become entangled in wool or livestock hair reducing wool quality. Burs can even become lodged in the eyelashes of livestock causing eye damage.
Management
You can play a role in reducing the spread of seeds, especially with houndstongue. Do not drive or walk in heavily infested areas if possible. Before you leave an infested area, pick all seeds from your clothing, pet or horse and throw them away. Wash vehicles, ATVs and equipment before going home. Purchase only certified noxious weed seed-free hay.
Houndstongue can be dug or pulled if conditions are right. It has a deep taproot that makes it difficult. You can collect plants with seeds and burn them. Seeds on a standing plant will stay viable for 2 to 3 years. Seeds in the ground will only stay viable for one year. Fall burning may destroy seeds. However, fire can also create the ideal situation and disturbance for houndstongue to thrive. Mowing is generally not effective. Grazing will contribute to the spread of houndstongue.
There are currently no approved biological control agents in the United States, because of negative effects on native plant species in the same family.
Because of its extensive taproot, herbicides are a good option for houndstongue. The best strategy is to spray plants during the first year. You can spray first-year plants well into the fall. You need to catch second-year plants in the spring or early summer before seeds mature. Commonly used chemicals include 2-4 D, Banvel, Cimarron, Escort, Telar or Tordon (restricted use). The fuzzy leaf can make herbicide penetration a challenge, so a surfactant is recommended. Always read and follow the entire label when applying herbicide. Common chemical names are used for clarity but does not imply endorsement of a product or brand.
For assistance on weed identification and control, contact the MSU Extension Office in Broadwater County at 406-266-9242 or the Broadwater County Weed District at 406-266-9243.
https://www.montana.edu/extension/broadwater/ ; https://www.facbook.com/broadwaterextension/
Article Images
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PhotoCredit: Allison Kosto
Image 1 Caption: Houndstongue Bugwood
Photo Credits: Allison Kosto
