Have you seen this plant in your plant beds? It is commonly known as Weedy Orchid or Broad-leaved helleborine (Epipactis helleborine) and has become quite a problem in Michigan and here at Woodlands South.
Controlling this plant is proving to be quite difficult. After consulting several MSU Extension specialists , there appears to be no magic bullet. There has been no research on the effectiveness of herbicides on this particular plant. This plant can grow up to two feet tall and will continue to spread throughout your garden if you do not take steps to control it. Pulling it is generally not effective due to its root structure. It is important to get all the roots because any pieces left in the soil can sprout new plants. Reports indicate that single doses of glyphosate (Roundup) are not effective. It has been suggested that trying products that contain 2,4-D or triclopyr (or both) may be effective as these will often control non-grass monocots. I personally have used and have had good results with Poison Ivy killer. Repeat applications may be necessary. It is important to always read and follow labeled directions to prevent injury to non-target plants.