A description of the flowering plants of this English county, the first to be published since the 1930s. Covering 1831 species with notes on habitat type, distribution, occurrence and historical information with latest dates recorded at various locations for rarer species. Over 600 species, including some rare species with interesting distribution patterns, are mapped, while some 77 species that can be found throughout the vice-county are listed. The maps show locations recorded within the past 25 years (1987-2012). The appendices contain all known extinctions with dates, details of interesting aliens recorded on Northampton Racecourse when it was an army camp during the First World War, and a Gazetteer of relevant sites and localities in the vice-county 32.