This dataset contains data collected for the following study: Weedy and seedy: the rapid evolution of life-history characteristics in an introduced daisy by Claire R. Brandenburger, Ben Maslen, William B. Sherwin and Angela T. Moles. The study was published in AoB PLANTS in August 2022 at https://doi.org/10.1093/aobpla/plac038. There are seven files, each containing plant life-history data collected during our experiment. Each file contains data for one characteristic except for germination.csv which contains data for two characteristics. The 'Family' column shows whether the plants came from the same original mother plant. The 'Population' column names the four Australian populations and one South African population sampled in this study. The 'Country' column shows which country (Australia or South Africa) the individual originated from. In the file 'totalseeds', the variable 'totalseeds' contains a count of the total number of seeds collected per plant. In the file 'seedweight', the variable 'seedweight' contains the average seed mass (mg) of all the air-dried seeds produced by each parent plant. In the file 'germination', the variable 'germinatedtotal' shows whether each seed germinated (1) or did not germinate (0); the variable 'viable' shows whether each seed was viable (1) or not (0) - this includes germinated or ungerminated seeds where the viability of ungerminated seeds was tested using a tetrazolium chloride stain; the variable 'germinatedviable' shows whether a viable seed germintaed (1) or not (0). In the file 'flowerbiomass', the variable 'pollen_received' shows whether each plant received pollen from its population (SAME) or whether it did not receive pollen (NONE); the variable 'flower_biomass_mg' is the total dried reproductive biomass (mg) produced by each plant; the variable 'total_biomass_mg' is the total dried vegetative biomass (mg) of each plant; the variable 'flower_weight_as_percent' is the percent (%) of the plant's dried biomass that was made up of reproductive biomass (calculated as 'flower_biomass_mg'/'total_biomass_mg'). In the file 'flowernumber', the variable 'flowernumber' contains the count of how many inflorescences were produced by each plant. In the file 'flowering2015', the variable 'flowering' shows whether each inflorescence flowered (1) or did not flower (0). R-code for our analyses is also available as part of this Dryad publication. More information on the methods and data analysis can be found in the full version of the published manuscript available from AoB PLANTS at https://doi.org/10.1093/aobpla/plac038.