Because it floats so well, whau was used by Maori to make rafts and fishing floats, European settlers called it corkwood but whau is half the weight of cork.
Whau only grows 6m high but it grows fast, up to 3m per year. This makes it a great tree for restoration projects where competition with weeds is always a problem.
Maori named an Auckland river after the whau tree and now it is being restored by the local community.
VISIT FRIENDS OF THE WHAU
Whau make a huge amount of seed in their final year. The record stands at 1,100,000 seeds for a single tree.
Whau is easily identified by its spiky seeds and long leaves. The leaves are usually 15-20cm long but they can grow up to 60cm on the warmer offshore islands like the Three Kings.
In this floatation experiment to test the claim of lightest wood (made by author JT Salmon in The Native Trees of New Zealand), neither wood (whau or balsa) was the clear winner.