Variable-leaf watermilfoil has long stems with whorls of finely divided leaves. This milfoil is rooted in the bottom of water bodies and arise to the surface of the water. When they reach the water, the stems turn and grow horizontally. The submerged leaves are feather-like and occur in whorls of 4 - 6. They are 1 to 2 inches long. The emersed leaves are stiff, longer than wide and have serrated margins. The flowers are small and reddish. Variable-leaf watermilfoil can reproduce by seeds or fragmentation and is an aggressive invader. Because of its tremendous growth rate variable-leaf watermilfoil can completely take over shallow ponds.