Myriophyllum verticillatum, the whorl-leaf watermilfoil or whorled water-milfoil, is a native to much of the North America, North Africa, and Eurasia. It closely resembles another native milfoil, called northern water milfoil (M. sibiricum) Whorled water milfoil is also easily confused with four types of invasive milfoils: Eurasian water milfoil (M. spicatum), Variable water-milfoil (M. heterophyllum), Parrot feather (M. aquaticum), and hybrid water milfoil (M. heterophyllum X M. laxum). In many areas it is an invasive aquatic plant. It is native in much of North America, the United Kingdom, Asia, and North Africa, and invasive to Ireland. Propagation and reproduction. Whorled water-milfoil reproduces by producing turions between September and November each year. These over-wintering turions sink to the bottom of the floor where they remain dormant until February [Caffrey,2006]. These fragments will give rise to numerous small thin roots that bed into soil to start growing in spring. The plants are monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and are pollinated by wind. Control and uses. Whorled water milfoil is a good water oxygenator in small quantities such as fish and frog ponds. It is also ideal in providing protection and respiration for fish spawn Management techniques of whorled water milfoil are not exactly known, but natural competition with other invasive aquatic plants has been the main control so far. There are a few management practices that some places are using, but they have not been approved for long-term usage.