An annotated checklist of the vascular flora of the Arezzo administrative province (Tuscany, Italy)

An updated and annotated catalogue of the vascular plants reported for the Arezzo administrative province (eastern Tuscany, Italy) is presented. The study tries to fill the gaps existing in the data at the sub-regional administrative scale, addressing relevant taxonomic and distribution issues, important not only at local level. The catalogue was compiled by gathering all the botanical information from various source types (old and recent floras, vegetation data, taxonomic studies, floristic and chromosome number reports, herbarium data, landscape studies, original field observations). More than 32,000 records were critically examined, georeferenced and stored in a floristic database. For many controversial taxa, considerations and case-by-case comments are reported in explanatory notes. A distribution map of report locations and a map of floristic information intensity (number of records per location) are provided. The total number of taxa registered is 2082, of which four Lycophytes, 42 Ferns and fern allies, 47 Gymnosperms and 1989 Angiosperms. In the total list, 1759 taxa were confirmed after 1950, 126 recorded before 1950, 116 considered inquirendae and 81 excludendae. Amongst the taxa confirmed after 1950, 1518 are native, 13 cryptogenic and 228 alien, of which 104 considered cultivated and 29 invasive for the Arezzo province. Data were analysed in relation to number of families, consistence of native and alien flora, chorological and general conservation aspects.