Naiads
Najas spp.

Naiads are underwater grasses with short, narrow leaves along slender, branching stems. Both native and nonnative naiads grow in non-tidal fresh waters and brackish tidal portions of the Chesapeake Bay and its rivers.

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Clump of brittle naiad grass on a muddy bottom.
Brittle naiad are a type of underwater grass that grow in non-tidal fresh, tidal fresh and brackish waters. (Photo courtesy of johnbotany/iNaturalist CC BY-NC, cropped)

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Appearance

Four species of naiads can be found in the Chesapeake Bay region:

  • Spiny naiad (Najas minor)
  • Southern naiad (Najas guadalupensis)
  • Slender naiad (Najas gracillima)
  • Northern naiad (Najas flexilis)

Naiads have slender, branching stems and short, narrow leaves. Leaves have pointed tips and a broadened base. Their leaves grow opposite each other or in whorls along each stem. Their small, fibrous roots have no rhizomes or tubers. The spiny naiad has stiff, curved leaves with visible teeth along the edges. The southern naiad has flat, straight leaves that are wider than other naiads’ leaves.

Predators

Migratory waterfowl such as mallards, pintails and lesser scaup feed on southern naiad and northern naiad. Slender naiad is not nutritious enough for waterfowl.

Reproduction and life cycle

Naiads reproduce sexually. Each plant has both male and female flowers. After the flowers are pollinated, seeds form in late summer. Seeds germinate and grow into new plants the following spring.

Did you know?

  • Southern naiad is also known as bushy pondweed and water nymph.
  • Migratory waterfowl such as mallards, pintails and lesser scaup feed on southern naiad and northern naiad. Slender naiad is not nutritious enough for waterfowl.
  • Although spiny naiad is not native to the Chesapeake Bay region, it is not considered invasive.
  • Northern naiads are particularly sensitive to changes in water quality and increased pollution.

Sources and additional information

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