A submerged aquatic plant rooted to the bottom with potato-like tubers attached to a root structure. Stems branch little until they reach the surface; just under the surface it branches profusely, forming thick mats. Leaves narrow, less than ¼ inch wide, ½-¾ inch long, not needlelike, finely toothed, in whorls of 5 (or 3-8). Leaf midrib is often red. The potato-like tuber attached to the root structure is a good way to identify it.
Similar species: Two species of Elodea are Missouri natives: Both lack tubers; the leaves are mostly in whorls of 3 or in pairs; and stems sparsely branched or unbranched. The non-native giant elodea or anacharis (Egeria densa), a popular aquarium plant, is sparsely branched, lacks tubers, has leaves in whorls of 4-6, and in Missouri occurs only sporadically and locally when it escapes from cultivation. Coontail (Ceratophyllum demersum) has needlelike, forked leaves and is bushy and heavily branched throughout.