Flowering rush removed from Spider Lake, Itasca County

(Released August 15, 2014)

Early detection of flowering rush and quick response to remove it from Spider Lake, have biologists cautiously optimistic about stemming its spread, according to the Minnesota Department of Natural Resources. First reported in Minnesota in 1968, flowering rush is an invasive aquatic plant known to be in 32 bodies of water in the state.
In late July, a localized patch of flowering rush was detected near the public water access on the east side of Spider Lake, near the town of Marcell. Following protocols in DNR’s rapid response plan, aquatic biologists surveyed the entire shoreline of the lake and found no further evidence of the plants. U.S. Forest Service, University of Minnesota Extension and the DNR collaborated to remove all of the identifiable plants. The lake is being designated as an infested water body and signs will be posted at public accesses to alert recreationists of the potential for reemergence.
“Although we performed a thorough search, there may still be submersed plants in the lake so we are asking people to keep a watchful eye and to let us know if they see more plants,” said DNR Aquatic Biologist, Rich Rezanka. ”Early detection and prompt removal can sometimes eradicate this plant from a lake, but diligence is critical in stopping it from becoming established.”
Flowering rush is a perennial aquatic herbaceous plant. It grows 1-4 feet high on an erect stem along shores in shallow water and produces umbrella-shaped clusters of pink flowers. In deeper water it grows submerged without producing flowers. Flowering rush is very difficult to identify when not in flower. It closely resembles many native shoreland plants, such as the common bulrush.

Homeowners and recreationists who suspect the presence of flowering rush are asked to report it to the DNR Ecological and Water Resources Division staff and not try to remove it themselves. The plant can spread if not properly and completely removed. Permits are required to remove plants in public waters.
Find more information about flowering rush and other invasive species on the DNR website at www.mndnr.gov/invasives.