The New Zealand Plant Conservation Network

All three were found at Pakiri beach estuary.
(Left to right)
The first was in the estuary/creek alongside Oioi. Oioi on the top edge of the bank with the other slightly more submerged. Maybe Juncus kraussii?
The second two were hanging out together in the sand near a creek bed. Both of these two were extremely sharp.

Sorry - smaller photo

Hi Katy, With the quality of the photo, I think form left to right Juncus kraussii subsp. australiensis(native), Ficinia nodosa (native), Juncus acutus (non native). Check them out on the site and see what you think. A good way to ID rushes is to cut the stem longitudinally which shows the internal composition. A book by B. Johnson called Wetland plants in NZ shows all of the rush species' insides. Oh and by the way the Ficinia nodosa is actually a sedge. I hope that helps. Cheers

Thanks Matt.

Yeah I had tentatively guessed Juncus kraussii and Juncus acutus. Ficinia nodosa makes sense.

Thanks for the heads up on the book. That should be really helpful.

Just confirming all of Matt's korero - all three wiwi correctly identified and the book (if you can still get it - is very useful)

Yes, Peter Johnson's book is my wetland bible.