Geographical distribution of ploidy
One-way analysis of variance (ANOVA) with Tukey’s mean-separation test procedure was used to determine the significance of differences in total range distribution (“extent of occurence of aquatic habitat” ahEOO km2: Murphy et al., 2019) for each of the three ploidy states. The same approach was used to examine differences in endemic and invasive species ploidy between gridcells and ecozones across world latitude bands. We measured variation in latitudinal range in °absolute (maximum latitude, minimum latitude, median latitude, and total latitudinal range) for a subset of 256 species from 11 aquatic plant families (Alismataceae, Araceae, Eriocaulaceae, Haloragaceae, Hydrocharitaceae, Isoetaceae, Lentibulariaceae, Nymphaeaceae, Potamogetonaceae, Ranunculaceae, and Typhaceae) for which both latitudinal range and ploidy information were available, see procedures in Murphy et al. (2020). We performed all analyses using R v. 4.0.2 (R Core Team, 2020).