Northern Prairie Wildlife Research Center
Western Wetland Flora
Field Office Guide to Plant Species
Ruppia maritima L.
- Family: Pondweed (Potamogetonaceae)
- Flowering: April-July
- Field Marks: This submersed aquatic with thread-like branches has terminal umber-like pairs of flowers. The nut-like fruits are borne at the ends of long stalks.
- Habitat: Alkaline or brackish water along the coasts; also in ponds, lakes, and ditches elsewhere.
- Habit: Submersed perennial with creeping rhizomes.
- Stems: Thread-like, much branched, up to 3 feet long, smooth.
- Leaves: All submersed, alternate, thread-like to linear, up to 4 inches long, more or less rounded at the tip, with a sheathing stipule at the base.
- Flowers: Usually borne in an umber-like pair at the tip of the stem, the stalks sometimes becoming spiral.
- Sepals: O.
- Petals: O.
- Stamens: 2.
- Pistils: Usually 4 per flower, free from each other, borne on an elongated, slender stalk, giving the appearance of 4 flowers in a cluster rather than 1.
- Fruits: 4, nut-like, ovoid, up to 1/6 inch long, usually with a short, curved beak. borne on a slender stalk 1/6-1 1/2 inches long.
- Notes: This species is sometimes placed in its own family, the Ruppiaceae. All parts of this plant are eaten by waterfowl. This species also provides excellent food and protection for fish.
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