Edible Wild Plants
John Kallas, authour of Edible Wild Plants and founder of Wild Food Adventures, completed a PhD on wild edible plants. This is certainly the most thoroughly researched book I have seen. I love it. I particularly appreciate John’s approach to foraging, particularly the importance of learning about plants growth, environmental influences, and tastes throughout the seasons. Not specific to Australia but most plants can be found here. Whilst it is not a book you want to carry on a long hike, it offers a lot more information than a field guide, including good photos of plants at different stages of their life cycle - critical to identification.
The Weed Forager’s Handbook
A great little field guide, specific to Australia, by Adam Grubb and Annie Raser-Rowland. On their webpage Eat That Weed, they have a distribution map of the 20 weeds - you can check this to make sure the contents are relevant to where you live.