Eurasian watermilfoil
Myriophyllum spicatum
Eurasian watermilfoil is a perennial, herbaceous aquatic plant that grows almost entirely submerged. Only the reddish flower spikes emerge above the water surface during the flowering period. The plant prefers nutrient-rich, standing, or slow-moving waters and can form dense mats.
Details
Oxygen production
High; produces significant amounts of oxygen directly into the water during photosynthesis.
Habitat function
Structure provider in water bodies, nursery for fish, habitat for zoobenthos.
Nutrient uptake
Efficient uptake of phosphates and nitrates from the water and sediment.
Food source for
Waterfowl, fish, snails.
Human use
Used as an aquarium plant, occasionally for phytoremediation.
Ecology
Ecological role
Important oxygen producer, provides shelter for juvenile fish and invertebrates, competes with algae for nutrients.
Natural predators
Waterfowl, herbivorous fish (e.g., grass carp), aquatic insect larvae.
Competitor species
Other macrophytes such as Potamogeton species or Elodea species.
Ecosystem service
Water purification through nutrient fixation, oxygen enrichment, erosion protection of the sediment.
Threats
Water pollution (extreme hypertrophy), mechanical control in recreational waters.
Scientific profile
Profile
Reproduction
Generative reproduction via seeds is possible, but vegetative reproduction dominates through fragmentation of stem sections and the formation of turions.
Protection & threats
Main threats
Not threatened in Central Europe; local declines may occur due to extreme herbicide pollution or mechanical weed control.