Bioclimatic data for native- and introduced-range localities of Polygonum cespitosum

To characterize P. cespitosum's climatic distribution, principal component analyses of temperature- and precipitation-related variables were conducted using bioclimatic data extracted (from WorldClim) for species occurrence data.

Methods
Persicaria longiseta (=Polygonum cespitosum s.l.) locality data include sample populations and species occurrences retrieved from GBIF.org. GBIF occurrence data were restricted to specimen-based records (i.e., herbarium specimens) containing latitude/longitude coordinates and/or specimen images. The original GBIF occurrence data are accessible here: GBIF.org (11th September 2018) GBIF Occurrence Download https://doi.org/10.15468/dl.cguuid

Occurrence records lacking location coordinates were manually georeferenced according to locality descriptions provided that the radius of uncertainty was <15 km. The data were subset horizontally (to contain only records with coordinates) and vertically (to include only four columns: gbif id, country code, latitude, and longitude). These data were concatenated with sample population location information. Bioclimatic data were extracted from WorldClim (Fick & Hijmans 2017) for locality coordinates at 2.5 spatial resolution using the raster package in R v.3.6.1.

Fick, S.E. and R.J. Hijmans, 2017. Worldclim 2: New 1-km spatial resolution climate surfaces for global land areas. International Journal of Climatology.