What is "horned pondweed"

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.

n. found in still or slow-moving fresh or brackish water; useful to oxygenate cool water ponds and aquaria [syn: Zannichellia palustris]