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Often referred to as wildcelery, tape grass, or eel-grass, Vallisneria americana (Michx.) is a dioecious (bearing staminate and pistillate flowers on different plants) freshwater perennial aquatic plant having fibrous roots (Lowden 1982). Along with Limnobium spongia and Elodea spp., American wildcelery belongs to the Hydrocharitaceae family.

In 1803 Michaux first described the North American Vallisneria plant as a distinct species, Vallisneria americana (Fernald 1918). However, many authors (e.g., Gray 1848, 1874; Chapman 1883; Britton and Brown 1913) named the plant a variety of the European species V. spiralis. Flower morphology and differences in pollination appear to be the major differences between the two species (Svedelius 1932; Kausik 1939). Sculthorpe (1967) suggested that V. americana may be a geographical race of V. spiralis. Current treatment recognizes the North American population as a separate species under the name V. americana (Lowden 1982). Lowden (1982) lists probable synonyms for V. americana Michaux var. americana as V. spiralis, V. gigantea, V. asiatica, V. subulispatha, V. neotropicalis, V. higoensis, and V. natans.

Vallisneria americana has linear submerged or floating leaves that are strap-or tape-shaped (Fig. 1), and may extend 2 m or more depending on water depth. The stem is veritcal with a short axis and bears stolons. Lowden (1982), who provided a detailed morphological description of V. americana from many North American locations, recognized both narrow- and broad-leaved forms of V. americana. In the former, leaves are less than 10 mm wide with 3-5 prominent longitudinal veins and margins entire to finely toothed. The leaf blade has perceivable to invisible transverse pigmented striations. This form is found in freshwater inland waterways, lakes, and lagoons. The broad-leaved form has leaves 10-25 mm wide with 5-9 veins and conspicuously toothed margins. The leaf blade has many visible transverse pigmented striations. This form is found in coastal freshwater inlets or spring-fed waterways subject to nearly constant temperatures. Many of these areas receive brackish water at high tide.