Waterweed, Brazilian Pondweed, Anacharis
A popular indoor aquarium plant. The plant is cold tolerant, and can be grown outdoors in milder areas of the UK, or treated as an annual in colder climates.
Synonyms: Elodea densa.
NB. This plant should not be confused with Lagarosiphon major (syn. Elodea crispa) which has been banned from sale since 2017.