These weeds are well known over most of N. Zealand. The leaves lie on the water and sometimes the roots don't go into earth at all but are simply submerged.
Specimen notes
Supplementary remarks:
This specimen is part of a collection given to the Allan Herbarium by Laurence Smith (Amberly office, Environment Canterbury). This was given to L. Smith in the early 1990's by someone in Port Robinson, Cheviot.
The collection is believed to have been collected in 1948, based on several specimens with fully written dates in the collection. We believe that JRK is a student of Canterbury Agriculture College (C.A.C), which is now known as Lincoln University.