Currently present in Montana!

Flowering rush is often sold as a water garden plant. It grows naturally in the slow moving waters of rivers and lakes, where these plants will spread when their roots are broken and dispersed.  Muskrats are one culprit of the spread of flowering rush, but boaters also contribute to the spread. Boats break the plant’s roots and transport these broken roots to new waters via the boat.

Potential Harms:

Flowering rush is a “pioneer,” meaning it’s attracted to waters not occupied by other plants. Currently present in Flathead, Lake, Missoula, and Sanders Counties, flowering rush is listed under Category 3 on Montana’s Noxious Weed List, which classifies it as having "the potential to have significant negative impacts."

Identification:

• Flowering rush leaves are tall, thin, and swordlike.
• Leaves can grow up to 5 feet tall.
• The flowers grow on a long leafless stem.
• 3 large and 3 smaller pink petals grow in an umbrella shape.
• Flowers bloom during the months of June to August.
• Flowering rush requires wet ground and full sun to grow.

Prevention:

Visit the Montana Weed Control Association’s “Weed ID” site (http://www.mtweed.org/weed-identification/) and get to know your local noxious weeds. Also, because of its designation as a Category 3 weed, the Montana Weed Association offers monetary rewards for reported sightings of certain weeds.

Links to more info on flowering rush:

http://fwp.mt.gov/fishing/guide/ANS/plants.html#floweringrush

http://www.mtweed.org/flowering-rush/

http://www.kingcounty.gov/environment/animalsAndPlants/noxious-weeds/weed-identification/flowering-rush.aspx