He has contributed significantly to the understanding of Australian plants, in particular numerous species of his home and workplace in the Wet Tropics of Queensland.
His contributions include many activities; he has collected eighteen thousand specimens and has named and scientifically described hundreds of species.
[4][5][6][7] A major project he worked on for approximately 45 years is the Australian Tropical Rainforest Plants identification key and information system (RFK).
This edition achieved the goal of making it freely available via the internet or via paid-for mobile apps for Android and iPhone.
[8] Both versions include fact sheets providing comprehensive descriptions for 2762 species, uses over 730 diagnostic features to make identifications, and contains around 14,000 images.