Milfoil News for the Western UP CWPMA

Dr. Ryan Thum of Grand Valley State University has confirmed the hybrid between Eurasian watermilfoil (Myriophyllum spicatum) and northern watermilfoil (Myriophyllum sibiricum) in Runkle Lake, in Iron County,Michigan. The Runkle Lake Association has contracted for Eurasian watermilfoil treatments in 2006, 2007, and 2008. The 2008 results were disappointing, and the applicator suspected the plants may be the milfoil hybrid.

Larry Bergwall sent me a live sample and I couldn't identify it. They seemed intermediate between Myriophyllum spicatum and Myriophyllum sibiricum. All the leaves I counted had about 12 leaflets per side.

John Skogerboe (US Army Corp of Engineers) passed on Dr. Thum's contact information, and Dr. Thum agreed to test a live sample. Results in October confirmed it to be the milfoil hybrid.

Here is a 2007 scientific publication about the hybrid milfoil. Figure 4 is especially interesting. (See attached file: Moody & Les 2007.pdf)

Ian Shackleford, Botanist

Ottawa National Forest