Growing in a water butt, probably come in with garden centre water plants from the North Island. It has now covered the water butt and spread to others nearby.
A native weed of ponds in Ayrlies
Little reddish plants floating on fresh water. I think they could be a fern?
Azolla (mosquito fern, duckweed fern, fairy moss, water fern) is a genus of seven species of aquatic ferns in the family Salviniaceae. They are extremely reduced in form and specialized, looking nothing like conventional ferns but more resembling duckweed or some mosses.