SafePlants

Hornwort: An Aquatic Oxygenator

Hornwort, scientifically known as Ceratophyllum demersum, is a popular submerged aquatic plant valued for its oxygenating properties and ease of care.

Considerations for Pets

• The text mentions that Hornwort has layered, hair-like foliage that can provide shelter for invertebrates in ponds, which could attract the attention of some pets.
• Hornwort does not put down roots, and parts of the plant may detach and float, potentially becoming accessible to pets.

Considerations for Children

• Hornwort has feathery foliage that might be appealing to children.
• As an aquatic plant common in ponds and lakes, children might encounter it in outdoor environments.

Nomenclature and Taxonomy

• Scientific Name: Ceratophyllum demersum
• Common Names: Hornwort, Coontail, Rigid Hornwort
• Family: Ceratophyllaceae
• Kingdom: Plantae (based on references to bryophytes and Kingdom Plantae)
• Synonyms: Ceratophyllum apiculatum, Ceratophyllum submersum (also mentioned as a separate species)
• Hornworts are bryophytes belonging to the division Anthocerotophyta. In some classifications, they were grouped as horned liverworts in the subclass Anthocerotidae (class Hepaticae).

Distribution and Habitat

• Hornwort is a British native and is widespread, found in still or slow-moving ponds, lakes, streams, and rivers.
• It's specifically mentioned in Iowa ponds and lakes.

Morphological Characteristics and Growth Habits

• Hornwort is a submerged aquatic plant that does not put down roots but can be anchored with weights.
• It has dark green, feathery foliage with branching stems that can reach up to 1 meter in length.
• The leaves are thread-like and finely divided. Ceratophyllum demersum (Rigid Hornwort) leaves divide no more than twice from their base, while Ceratophyllum submersum (Soft Hornwort) leaves divide 3-4 times.
• It grows loose in the water.

Ecological Role

• Hornwort is an excellent oxygenator for ponds and aquariums.
• It helps to clarify water and minimize algae growth.
• It can become so thick in some lakes that it impedes boat traffic.
• It provides shelter for invertebrates from predators and is used by fish as a spawning medium.

Quirky Facts

• The name "hornwort" comes from the elongated, horn-like spore-producing structures of the plant and the division of leaves suggesting horns.

Interactions with Other Organisms

• Hornwort shelters invertebrates from predators.
• It's used by fish as a spawning ground.

Further Information

• RHS (Royal Horticultural Society) provides information on Ceratophyllum demersum.
• Information about Hornwort is available at animal-world.com.