Motivation: Studies of biological invasions are limited by availability of comprehensive lists of species that have been introduced. Most lists of introduced species are limited to "successful" introduced species that have established at least one population; data about introduced species that fail to establish is very rare yet is highly informative for understanding factors affecting invasion success. This data paper describes the content, compilation methods and planned updates of the IntFloraAus dataset. IntFloraAus contains a comprehensive, taxonomically standardised list of all known alien vascular plant species that have been introduced to Australia, along with selected species characteristics. Uniquely, the dataset includes information about introduced species that have failed to naturalise, enabling comparisons across different statuses of biological invasion (i.e. introduced, naturalised and invasive). Such lists can also identify changes in patterns and processes in biological invasions overtime if they are maintained and updated. For instance, more species may be introduced and previously introduced species may go on to naturalise or become invasive given time and with synergistic processes such as climate change. Data on introduced species can also be used to assess effectiveness of biosecurity measures and to gain understandings of ecological processes such as changes to native floras. Main types of variables included: The dataset includes a comprehensive list of 34,650 plant species that are known to have been introduced to Australia since 1770, 4,081 of which are classified as naturalised and 428 as invasive. Data on plant characteristics includes: invasion status in Australia, growth forms, and three factors related to species introduction histories (native regions, introduction pathway, and minimum residence times in Australia). Spatial location and grain: The dataset applies to the six states and three mainland territories of Australia (mainland plus Tasmania) as a single location and grain. Islands or territories away from mainland Australia are not included. The dataset is global when considering species' native range; this grain size ranges from countries to continents. Time period and grain: Records in the dataset span from 1770 to 2023.

Human introduction of species around the world is not exhaustive. Comparing characteristics of non-native species that have been introduced with characteristics of non-native species that could be introduced can reveal biases in which species were introduced in the past, and can highlight future threats. We test for introduction biases in non-native trees introduced to Australia using a dataset of 57,958 tree species known globally. We found that: (1) non-native species were selectively introduced, and do not form a random subset of all non-native species, though (2) they do represent the functional trait-space occupied by tree species globally; (3) trees naturalised in numerous countries and introduced for more uses are more likely to be introduced in Australia; and (4) introduction debt can indicate characteristics of potential future non-native introductions. For Australia, tree species from the tropics and global south pose an especially high future invasion risk.