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Weed of the Week: Hound's Tongue

The petals of the noxious weed, Hound’s tongue (Cynoglossum Officinale), may remind you of a dog’s tongue, happily hanging out the side of his mouth.  But behind this plant’s elegant rosy petals is a bite worth noting.

Invasive plants flourish and spread vigorously, causing harm to the environment, economy, and public health. According to the International Union for Conservation of Nature (IUCN), invasive plants are the second greatest threat to biodiversity. 

Hound’s tongue was first recorded in Canada, 1922. This noxious weed has spread quickly and is estimated to infest more than 2,000 hectors in BC. The “unwanted” plant can be found in BC’s Kootenay, Okanagan, Thompson, and Cariboo regions.  Thriving on gravelly surfaces and shady locations, hound’s tongue has become a common guest of damp fields, forested areas, and roadsides.  As you drive by you may catch a glimpse of the plant’s reddish purple petals. This weed’s five petals are self-pollinating, and bloom between May and July. Hound’s tongue stems stand up to 1.5 meters tall and display lance shaped, rough, and hairy leaves.

A key component to the spread of hound’s tongue is its hooked seeds that easily attach to animals, clothing, and equipment.  More than 600 hooked prickles are produced by a single plant. This specific characteristic of hound’s tongue is very bothersome to livestock whose eyes are especially irritated by the presence of barbed seeds. The seeds are also a common annoyance to outdoor enthusiasts. 

This plant is detrimental for the livestock industry; hound’s tongue contains toxic alkaloids which are potentially damaging to the liver of both horses and cows.  This plants’ poisoning effect may bring on a host of symptoms such as convulsions, jaundice, and diarrhea. The reduced fitness and weight of livestock can decrease the animal’s sale value.  Grazing pastures are also devalued by the spread of hound’s tongue.

Steps to manage hound’s tongue can be achieved by strategies such as hand pulling, mowing, biological control, as well as chemical. You can help protect your community’s local resources by taking action against this invasive plant.

To find out more about Hound's Tongue, click here.

In Your Words...

  • “Working with the Hot Spots crew in Saanich in 2010, we practiced different methods to treat knotweed with glyphosate using the injection gun on several sites. With these skills I was able to implement Saanich's first knotweed eradication pesticide treatment program for private properties.”

    Donna Wong, Environmental Stewardship Officer, District of Saanich

  • “Thank you for orchestrating access to the Hot Spots crew for GINPR.  This crew allowed us to move the restoration project on Princess Margaret ahead by months if not by years.”

    Wayne Bourque, Superintendent of Gulf Islands National Park Reserve, Parks Canada

  • "We had a great hike at Kenna Cartwright Park. The kids built a snowman and we all enjoyed the views. The outreach worker showed us some plants that don't belong in the park, gave us info about them and what to do about them, and gave us all some cool gifts from the Invasive Plant Council. Thank you!"

    Susan Hammond, Kamloops Young Naturalist Club

  • “Parks Canada and Canadians have benefited from the partnership to have on-the-ground Hot Spots crews, and we would be happy to work with a crew in the future at one of our many national parks and national historic sites that are in need of invasive plant management.”

    Brian Reader, Species at Risk Manager, Parks Canada

  • “I am impressed with the coverage of the GIS mapping data now available. I will be developing an Invasive Species Management Plan for Pacific Spirit over the next several years and these maps will help as a coarse indication of current conditions, and in guiding initial inventory and monitoring efforts.”

    Markus Merkens, Pacific Spirit Park area manager, Metro Vancouver

  • “Our crew has finished their work at Fort Rodd Hill National Historic Site and Gulf Islands National Park Reserve. I want to thank you, on behalf of Parks Canada, for providing the crew to us. They were well-trained and got a lot of important restoration work done in our nationally-important heritage areas.”

    Brian Reader, Species at Risk Manager, Parks Canada

Weeds in British Columbia

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