Professor Ladiges is distinguished for her studies of systematics, biogeography and ecology of Australian plants. She is best known for her innovative approach to resolving uncertainties about the classification and naming of Australia's most important group of trees, the eucalypts. She was the first to employ modern methods and DNA sequence comparison to establish definitively the relationships of the major groups of eucalypts and establish the basis of a robust classification, important to industry and biodiversity conservation. The methods she has developed for biogeography represent a major theoretical breakthrough, enabling analysis of relationships and evolutionary history of areas of endemism.