The Collaborative International Dictionary
Anarcharis Canadensis
Pondweed \Pond"weed`\, n. (Bot.) Any aquatic plant of the genus Potamogeton, of which many species are found in ponds or slow-moving rivers.
Choke pondweed, an American water weed ( Anarcharis Canadensis, syn. Elodea Canadensis.) See Anacharis.
Horned pondweed, the Zannichellia palustris, a slender, branching aquatic plant, having pointed nutlets.