Rigid Hornwort
Ceratophyllum demersum
Rigid Hornwort is a perennial, submerged aquatic plant that lacks true roots. Its dark green leaves are stiff, dichotomously branched, and arranged in whorls along the stem. The species thrives in nutrient-rich, still or slow-moving waters across the globe. Due to its rapid growth, it plays a significant role in oxygenating the water and sequestering excess nutrients.
Details
Oxygen production
Very high; one of the most effective plants for oxygenating stagnant water bodies.
Habitat function
Serves as a spawning substrate for fish and a refuge for zooplankton.
Nutrient uptake
Very strong; absorbs nutrients like nitrate and phosphate directly from the water through the leaf surface.
Food source for
Waterfowl (e.g., ducks), herbivorous fish, and various aquatic snails.
Human use
Popular aquarium and pond plant used for algae control and water clarification.
Ecology
Ecological role
Produces large amounts of oxygen and provides shelter and habitat for juvenile fish and insect larvae.
Competitor species
Competes with algae and other aquatic plants such as Elodea species for nutrients.
Ecosystem service
Water purification through nutrient elimination and suppression of algal growth (allelopathy).
Threats
Habitat destruction through mechanical clearing or extreme herbicide exposure, though generally not endangered.
Scientific profile
Profile
Reproduction
Both generative via hydrophilous seeds and highly effective vegetative reproduction through shoot fragmentation and the formation of turions.
Protection & threats
Main threats
Currently not threatened in Central Europe; local threats include extreme herbicide pollution or massive mechanical clearing of water bodies.