This plant is also called the Piedmont watermilfoil, or the lax watermilfoil. Loose watermilfoil is a native submersed plant. It is listed by the U.S. Fish and Wildlife Service as a potentially endangered species. Loose watermilfoil grows in shallow or relatively deep waters including lakes and ponds, streams, ditches, and canals. Here it is growing in a clear-water lake in central Florida.
The stems of loose watermilfoil are reddish. They are slender and grow to several feet long. There is not much branching. The grayish-green leaves are typical of submersed watermilfoil leaves. They are limp, divided, and somewhat feathery looking. However, these leaves are even finer and more delicate. They are an inch or two long. The leaves are in whorls of 4 or 5. The flowers of loose watermilfoil are on a spike, which is actually the continuation of the main stem. The minute flowers are translucent, and pinkish to reddish. The submersed leaves of the native watermilfoil are finely divided. They are even more delicate than those of other watermilfoils. The leaves are in whorls of 4 or 5. The flower spike looks bare because the pinkish flowers are so small.