Boulia is in the channel country of western Queensland. Here graduate and undergraduate students in biogeography, plant systematics and ecophysiology have established long-term studies on several populations of the Waddi tree (Acacia peuce). This interesting and long-lived (500+ years) wattle has two different leaf forms. The branches on young trees are pendulous and the leaves rigid with sharp points. Is this a response to herbivory by megafauna? The canopy of older trees lack the sharp points and branches are more spreading. The trees are locally dominant on stony flats associated with ancient river beds. Surrounding vegetation ranges from sparse open woodland to chenopod and grassland communities depending on soils and topography.