soft hornwort

Ceratophyllum submersum is a free-floating aquatic plant that lives submerged in freshwater environments. It is closely related to Ceratophyllum demersum, another species in the same genus. The plant is found in a range of regions including the Afrotropical, Nearctic, Neotropical, and Palaearctic zones, as well as in specific locations such as Denmark, Finland, Bulgaria, and the Baltic Sea. It has also been reported in the Atlantic Ocean and various other parts of the world.