Houndstongue (Cynoglossum officinale)


Common names:

Houndstongue, common houndstongue, gypsy flower, rats and mice, dog bur

Scientific Name:

Cynoglossum officinale


Houndstongue is a member of the Boraginaceae (Borage) family. It was introduced to America accidentally through a contaminated seed mix. All parts of this plant are hairy. The leaves are alternate, rough, lacking teeth or lobes, and are 1-12 inches long. The flowers grow in long, coiled clusters at the end of the branched stems and have 5 lobes. It reproduces exclusively by seed, and one plant can produce hundreds of seeds that grow inside groups of 4 nutlets and are covered by hooked barbs.

Life cycle:

Biennial or short-lived perennial

Height of mature plants

1 – 4 feet

Flower color:

dull reddish-purple

Bloom time:

June – July


Houndstongue looks similar to other species in the borage family such as bluebell and bugloss species species (Mertensia spp.and I spp.), which both have blue flowers. It also looks a bit similar to common mullein (Verbascum thapsus), which has yellow flowers and much fuzzier leaves.


Houndstongue often grows in shady forest understories and pine woodlands, but can also do well in grasslands, pastures, meadows, and along roadsides and other disturbed areas. It grows best in coarse, sandy soils, but can also do well in wetter grasslands.


Houndstongue is a highly invasive plant, especially in eastern Oregon. It can reduce the value of forage and competes with both native and desirable grasses. It’s seeds have hooked barbs that can reduce the value of sheep wool, cause physical damage to animals, and also allow it to easily spread by cattle and wildlife. Furthermore, this plant is toxic to humans and livestock.

Noxious Weed Listing:


Asia and Europe


Oregon Noxious Weed Profile
Washington Noxious Weed Profile
King County Noxious Weed Profile
Invasive.org profile
CABI Invasive Species Compendium

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