The dataset contains a current inventory of vascular plant species and their attributes present in the flora of Britain and Ireland. The species list is based on the most recent key to the flora of Britain and Ireland, with taxon names linked to unique Kew taxon identifiers and the World Checklist of Vascular Plants, and includes both native and non-native species. Attribute data stem from a variety of sources to give an overview of the current state of the vascular flora. Attributes include functional traits, distribution and ecologically relevant data (e.g. genome size, chromosome numbers, spatial distribution, growth form, hybridization metrics and native/non-native status). The data include previously unpublished genome size measurements, chromosome counts and CSR life strategy assessments. The database aims to provide an up-to-date starting point for flora-wide analyses. Full details about this dataset can be found at https://doi.org/10.5285/9f097d82-7560-4ed2-af13-604a9110cf6d