Bamboo is a useful as well as attractive plant to have growing nearby. We don't have any native bamboo, so I'm pleased that folks imported it a long time ago.
We have a very useful native plant down here called NZ Flax. It isn't closely related to linen flax, but some strains of it yield a very strong fiber. Before synthetic fibers were commonly used, there was quite an industry here producing rope and twine from flax. Our Maori folk used it for all sorts of things as you can well imagine.
I use it for tying up my tomatoes. I don't extract the fibers, I just tear the leaves into narrow strips. While I also use synthetic cord for garden work, I'm using more and more flax nowadays. It is a renewable material, and at the end of the tomato season I can throw my natural string in the compost bin.
There are two main types of flax. There is a small, softer variety we call mountain flax or Phormium colensoi. It has relatively small, weak leaves. The bigger, stronger type is known as Harakeke or Phormium tenax. Harakeke can grow to over six feet tall and it provides the best cordage (the Maori recognized many different varieties of Harakeke... some are evidently better than others for some purposes).
While it looks beautiful, NZ flax can be a nuisance in some gardens. It needs to be regularly trimmed, and if the leaves get caught up in your lawnmower or weed-whacker blade you can get quite a tangle. You might even get pulled off balance by a tangled weed-whacker. The flowers and very attractive and birds feed on the nectar produced.
Here is a Phormium tenax plant growing just across the road from my home. Behind it is another native plant which produces cordage, the cabbage tree (Cordyline australis). It, too, can really tangle your lawnmower blade with its fallen leaves.
