One of Australia’s rarest plants, the Waddi Tree (Acacia puece), has a spiky, needle-like leaf and thick bark. The Waddi Tree piqued early explorer William John Wills’ interest, with some samples of the seeds found buried in his diary after his death. The extreme hardness of Waddi wood was put to a number of uses by the local Aboriginals and European settlers. Now a protected species you can find these trees on the fringe of the Simpson Desert in Queensland and the Northern Territory....