The file "10.1111oik.03956-data.xls" contains records for 34 plant species (rows) for the following traits (columns): Scientific.name = scientific plant name Plant.clade = clade that a plant belongs to Plant.order = order that a plant belongs to Latitudinal.class = plant species were classified to either temperate or tropical (includes subtropical) origin Dutch.status = whether a species is native to the Netherlands Functional.group = the functional group that a plant belongs to (emergent, submerged) Allelopathic.potential = the measured allelopathic potential using agar bioassays (in mm; diameter of clearing spots) N = nitrogen content of foliar material (in % of dry mass) C = carbon content of foliar plant material (in % of dry mass) P = phosphorus content of foliar plant material (in % of dry mass) DMC = dry matter content of foliar material (in % of wet mass) Total.phenolics = total phenolic content of foliar material (in mg g-1 dry mass Acquisition = whether plants were collected in the field or ordered from a plant breeder greenhouse = whether plants were kept in the greenhouse Total.sugars = total amount of free soluble sugars (in mg g-1 dry mass) The file "10.1111oik.03956-phylogenetic-tree" contains the phylogenetic distances for the aquatic plant species involved. This file was used for the phylogenetic analyses.