My research is in the systematics and phylogeny of Southern Hemisphere plant families, especially Australian Restionaceae and the allied Poalean monocots Anarthriaceae and Ecdeiocoleaceae. Former projects included phylogeny of Proteaceae and Myrtales, and description of Australian species of Ranunculus, Veronica and Plantago. I have collaborated with others in the Monocot Phylogeny Group in the phylogeny of Poales and Liliales. Another interest has been the complex flowering behavior of the species of Ecdeiocoleaceae, a grass-like Western Australian plant group.
Currently I am preparing a treatment of Restionaceae, Anarthriaceae and Ecdeiocoleaceae suitable for on-line publication in the Flora of Australia. These are rush-like plants, closely related to the Poaceae (grasses) with major concentration of species in Western Australia. This will incorporate changes in classification arising from a DNA-based phylogeny of the restiid clade developed with colleagues. It includes preparing keys for species identification, descriptions, bibliographies and synonymies for 159 Australian species. Several genera have been almost fully updated in the format of the Flora. Some names have been lectotypified to clarify their application.