Andrew Mitchell has worked in the natural resource management field for all of his career, working mainly in the Western Australia rangelands for the WA Department of Agriculture. Initially he was based in in the Kimberley and moved to Darwin in 1999. When he turned 60 in 2009, he left the Commonwealth in Darwin and took up the consultancy trail in Perth, where he mainly works on arid zone and tropical botanical surveys and associated plant identification. David Wilcox was a consultant in Natural Resource Management and the Principal Rangeland Management Officer in the Western Australian Department of Agriculture until 1986. Wilcox was the recipient of numerous honours from many pastoral associations and scientific bodies. Wilcox bush and Acacia wilcoxii are named after him. David Wilcox and Andrew Mitchell were the authors of the first and second editions of this book, with photographs taken by Ernie Laidlaw. Sadly, David Wilcox died in 2015 and Ernie Laidlaw died in late 2022. The updated text of this edition has been written by Andrew Mitchell. The majority of the original photographs were taken by Ernie Laidlaw on 70 mm colour positive film. After 2010, most of the additional photographs were taken by Andrew Mitchell with a digital camera. Photographs not taken by Laidlaw or Mitchell are attributed to their owners.