Philip Short recently faced the problem of having established a plant genus that turned out to be a homonym of an earliernamed genus. In 2014, he erected the name Roebuckia for a range of daisy species in his review of Brachyscome. However, Roebuckia had already been established as a name for a fossil (Early Cretaceous) plant from Western Australia by myself (McLoughlin, 1996). Because homonyms are illegitimate according to the International Code of Nomenclature for Algae, Fungi and Plants (McNeill et al., 2012), Philip was obliged to establish a new name (Roebuckiella) for those species he had previously assigned to Roebuckia (see Short, 2015). How, then, can one be sure that when establishing a new genus, the chosen name has not been used before?