Exotic weed propagules (seeds or fruits) often contaminate goods intended for import into Australia. Biosecurity officers must identify such propagules to manage risks, prevent incursions, and decide on potentially costly actions such as cleaning, treating, or destroying cargo. According to observations made by the Australian Department of Agriculture and Water Resources, more than 20% of the propagules found by biosecurity officers currently cannot be identified. By far the most important weed families contributing to seed load of imported goods are the grass family (Poaceae) and the daisy family (Asteraceae), accounting together for approximately 80% of cases. To facilitate fast and secure identification, increase the capabilities of biosecurity staff, and reduce the risk of weed incursions, we have developed an interactive digital identification key to the propagules of an initial priority list of 43 species of Asteraceae.