Water-willow is a perennial that is common along stream and lake margins. Water-willow grows to 3 feet tall and often forms dense colonies that help stabilize shorelines. The stems do not usually branch and have prominent whitish lines. The leaves are opposite, long and narrowly tapered (up to inches 6 long and ½ inch wide) with smooth margins and a distinctive whitish midvein. The leaves look very much like those of the willow tree. Water-willow flowers from May through October. The flowers are on long stems originating from the base of the leaves. Flowers are 5-petaled orchid-like (3/4 inch diameter), white with purple/violet streaks on the lower petals. Water-willow can spread from seeds and forms extensive rhizomes by which it forms colonies and spreads rapidly.
Submerged portions of all aquatic plants provide habitats for many micro and
macro invertebrates. These invertebrates in turn are used as food by fish and other wildlife species (e.g. amphibians, reptiles, ducks, etc.). After aquatic plants die, their decomposition by bacteria and fungi provides food (called “detritus”) for many aquatic invertebrates. Deer will browse the leaves while beaver, muskrat, and nutria will consume the rhizomes of water-willow.