A few thoughts on foraging resources. Firstly, as Euell Gibbons writes, you do not need to be a botanist to be a forager. Secondly, there are many ways to learn to safely identify plants - books, internet resources, other experienced foragers, courses.
I do not think that any resource in itself is the answer to becoming a competent forager - it is a combination of curiosity, enthusiasm, common sense, and experience that will lead you to this point. Resources help us to do that more safely, and add richness to our understanding. For tips on my approach to learning how to forage, see my guide Foraging for Food.
Each of the resources listed here have been helpful or interesting to me in some way on my foraging adventure. If you have a resource not listed that you would recommend, I would love to hear from you.
Books - edible weeds
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.
Stalking the Wild Asparagus
Euell Gibbons (1911-1975) is a man who I would have liked to have had a dinner party with. Written in 1962, this book, whilst outdated in some cultural ways, describes a man who was ahead of his times - hosting wild food dinner parties before they were a food trend. Euell was clearly passionate about finding wild food sources. He talks about the need to learn to observe plants through there life cycle and to see these plants as having their own flavour profile and uses, attempting to avoid the desire to simply use wild plants to replace recognised and comfortable food sources - a similar message to John Kallas. The plant descriptions are often part story, with suggestions for methods of preparation and use in meals. The drawings are minimal and are black and white so not the best option for identification. A good read nonetheless.
Books - Australian native plants
Wild Food Plants of Australia
This field guide by Tim Low offers a brief summary of native Australian plants with a colour photo and distribution. Some basic uses are identified. It is small and easy to carry around on walks. I guess I prefer a little more detail - I would love to see this guide re-published with a range of photos through the plants life cycle to help with identification. But this and a smartphone are a good combination!
Food history books
The Oldest Foods on Earth
A exploration of food history and food culture in Australia by John Newton.