Water celery is not native to Washington, but it does not tend to crowd out native vegetation or take over our lakes like invasive nonnative plants such as Eurasian watermilfoil. Therefore, it has been included under the native plant category.
Water celery is known by its scientific name, Vallisneria americana, and also by other common names such as tapegrass, wild celery or eel grass (not to be confused with the marine eel grass, which is a different plant). It is native to eastern North America, and is an example of a plant that has been introduced to our region, but has not become particularly weedy. It was originally introduced to provide forage for wildlife, as it is a favorite food of waterfowl. Presently it is found both in eastern and western Washington, especially in lakes with low alkalinity.
Water celery is an attractive plant. It has long ribbon-like leaves that grow from a root- stock anchored in the sediment. Most often the plant is completely submersed, though in shallower water sometimes the leaves will grow long enough (up to 2 m (6 ft) long) to float on the water surface. The leaves are about 1/2 inch wide with a broad stripe down the middle. This broad stripe is composed of many tiny veins with occasional cross veins, and can be used to distinguish water celery from similar looking submersed forms of burreeds or arrowheads. New plants will form from buds along the horizontally spreading roots of the parent plant.
Water celery has developed an interesting pollination strategy for dealing with its watery environment. The female flowers rise to the surface on corkscrew shaped stalks. On the surface the cylindrically shaped flower will form a slight depression in the water surface. The tiny male flowers are formed on different plants in special underwater chambers. When the male flowers are mature the chamber opens, and the flowers float to the surface. At the surface they open their 3 petals to form a little raft with the pollen-covered anthers acting as sails. The male flowers will drift around freely in the wind and current, until they encounter the depression created by the female flower. At that point the male flower falls into the female flower, depositing its pollen along the way. After pollination, the female flower is usually drawn beneath the water surface on its coiling stalk. It elongates to a 2-3 inch long cylinder as the seeds mature. Eventually many tiny seeds are released into the water as the cylinder decays. So long as the seeds do not dry out, they can germinate into new plants.
Because water celery does not tend to crowd out native aquatic plants, it can provide good habitat in a lake. Diving ducks eat the buds on the root runners, while other waterfowl and muskrats eat the foliage and seeds. Fish find the long leaves to be good spawning habitat, and it provides cover for juvenile fish. Even humans in Japan will harvest the leaves of Japanese water celery for food. However, even though water celery is generally considered to be a beneficial plant, please do not introduce it or any other aquatic plant to new locations.