A seedling of the golden wattle, Acacia pycnantha, from Australia, growing on the site of a fire which all but destroyed the surrounding woodland just six months previously. The single, waxy- looking 'leaf' in the centre is not in fact a true leaf, such as those surrounding it, but a flattened leaf stalk (petiole) called a phyllode. The seedling puts out the true leaves early in its development but following a phase change which occurs as it matures only phyllodes are formed (note however that adults of other species of wattle may have a mixture of leaves & phyllodes or even just leaves). Phyllodes are a common Australian leaf modification for conserving water.