Images by Jeremy R. Rolfe and Dennis Gordon.

Abundant from lake margin to c. 4 m depth. Growing in fine silica sand with most of the foliage immersed in algal and cyanobacterial flock. Usually found in sheltered sites near stands of kutakuta (Eleocharis sphacelata)

Kaiiwi Lakes are probably the stronghold now for this endemic, especially as it seems likely that South Island plants attributed to this species are another allied, but unnamed species.

Dennis Gordon's excellent image shows a plant stripped of the surrounding sediment that has both male (red) and female flowers.