Callitriche heterophylla Pursh.
Engl.: two-headed water-starwort.
Classic texts: King's 1898.
Henriette's herbal is one of the oldest and largest herbal medicine sites on the net. It's been online since 1995, and is run by Henriette Kress, a herbalist in Helsinki, Finland.
http://www.henriettes-herb.com - Copyright 1995–2021 Henriette Kress.