Hippuris tetraphylla

Hippuris tetraphylla

Hippuris tetraphylla L. f.
Engl.: four-leaved mare's tail.
Suom.: nelilehtivesikuusi.
Sven.: ishavshästsvans, bred hästsvans, bredbladig hästsvans.

I have no articles for this botanical term, but there might be some for the next level down (if found).