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Washington State Department of Ecology > Water & shorelines > Freshwater studies > Lake water quality > Aquatic Plant Guide home > Plant-like Algae > Nitella

Aquatic Plant Identification Manual for Washington's Freshwater Plants

Plant-like Algae

Species: Nitella sp., nitella, brittlewort
Family: Characeae

Nitellas are bright green algae that often are mistaken for higher plants because they appear to have leaves and stems. These long, slender, delicate, smooth-textured algae lie on the bottom of a lake or pond and are seldom found in the water column. Whorls of forked branches are attached at regularly spaced intervals along the "stems". Nitellas sometime grow together with muskgrasses (Chara spp.), another plant-like algae, to form underwater meadows.
Plant-like Algae Icon
Leaf: No true leaves. Six-eight evenly forked branchlets grow in whorls at regularly spaced intervals along the "stem". Unlike the rough branchlets of most muskgrasses (Chara spp.), nitella branchlets have a smooth texture.

Stem: No true stems. Hollow, stem-like structures have whorls of forked branches along their entire length. The largest nitella species have "stems" up to 2 m long.

Flower: Does not bear flowers. Instead nitellas have microscopic spore-producing organs. Male organs grow at the base of the branchlets. Female organs are located in a cluster on the sides of the branchlets below the male organs.

Fruit: Produces spores rather than fruits. 

Root: Lacks roots. May be attached to the bottom by root-like structures called holdfasts or floating free above the sediment.

Propagation: Spreads by spores transported by wildlife and also will form new plants from vegetative fragments.

Importance of plant: Provides cover for fish, food for fish and waterfowl, and stabilizes the sediment. Because nitellas have no roots, they remove nutrients directly from the water. Nitellas are considered desirable species in Washington.

Distribution:  Worldwide. More than 30 species are reported to occur in the U.S.

Habitat: Nitellas are found growing in shallow to deep waters of soft water or acid lakes and bogs. They often grow in deeper water than flowering plants and frequently form a thick carpet or grow in clumps along the bottom.

May be confused with:  Muskgrasses (Chara spp.), which usually have unforked branches and a distinctive, unpleasant garlic odor, especially when crushed. Another algae, Tolypella, has unevenly forked branches in contrast to the evenly forked branches of the nitellas. Nitellas may also be confused with two vascular plants: water-nymphs (Najas spp.), which have opposite leaves, and coontail (Ceratophyllum demersum), which has leaves that fork into several segments.

Photographs: Nitella sp. closeup

Line Drawings: Nitella sp. 

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