Curly-Leaf Pondweed; Curly Pondweed
Potamogeton crispus L.
Potamogetonaceae (the Pondweed Family)
General: An aquatic plant having a life history similar to that of a winter annual. Like most aquatics, stems and leaves are lax and weak when removed from water, and the plants quickly wilt and dry.Stems: Somewhat flattened, sometimes with a few branches, to as much as 2 m (6.6 ft) long. No rhizomes.
Leaves: Strap-shaped, with undulating and finely serrate (toothed) edges, especially towards the tip. All leaves are submersed (none are modified for floating on the surface). Stipules are free from the leaves except at the base. Leaves are generally alternate on the stem.
Flowers: Small, inconspicuous, and perfect, with four tepals, stamens, and (usually) ovaries. Flowers arranged in a dense spike about 1-2 cm (about 0.4-0.8 in) long.
Fruit: Small, hard, flattened, and about 3 mm (0.12 in) across, with a pointed, straight or somewhat curved beak nearly as long.
Turions: Rigid, corkscrew-shaped, and about 1.0-1.7 cm (0.4-0.7 in) long. Produced at ends of branches, breaking off in mid- to late summer to produce new plants.
Habitat: Found in a variety of aquatic habitats, including permanently flooded ditches and pools, rivers, ponds, inland lakes, and even the Great Lakes. Prefers alkaline or high-nutrient waters.
Sources: Voss (1972), Catling and Dobson (1985), Gleason and Cronquist (1991), Haynes and Hellquist (1999).
Updated January 2006