Egeria densa - Visit ITIS for full scientific classification.
- Submerged waterweed forms dense mats.
- Has long stems, single white flowers (3 petals) at water surface.
- Leaves are smooth and narrow, with teeth on edges and no stalks, placed in groups along stems.
- Looks like Hydrilla, except that upper and middle leaves are 1/2" - 1 1/2" long.
- It looks larger and leafier than Hydrilla.
- Often has 4 leaves per group.
- The similar Elodea often has 3 leaves per group.
- Still or slow-moving, freshwater habitats with high nutrient levels.
- Grows best under low light (~100 lux), tolerates turbidity and brief time under ice.
Invasion Pathways and Distribution
- Introduced from eastern South America as an aquarium plant.
- Can infest when it is discarded from an aquarium into freshwater habitats.
- Occurs in several areas of California and it is expected to spread to new areas.
- In U.S. plants only produce pollen-bearing flowers.
- Can grow and infest from pieces.
- Aggressively invades new areas, displacing other plants and changing aquatic ecosystems.
- Forms dense, submerged mats that reduce water flow, interfere with boating and fishing, and clog pumps needed for irrigation, water supply, and flood control.
- California State Parks - Division of Boating and Waterways conducts a control program in the Sacramento-San Joaquin Delta.
References and Useful Links
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