Box plots of four quantitative characters, leaf length (A) leaf width (B) number of leaf lateral vein pairs (C) and inflorescence length (D) of Persicaria rotunda and P. jucunda. The boxes (rectangle region) represent the interquartile range and the whiskers (vertical line) represent the range excluding the outliers (circles). The three upper, middle and lower lines on the boxes represent the 75%, 50% and 25% of the variables, respectively. The upper and lower ends of the whiskers represent the maximum and minimum values of the variable, respectively. The circles represent the single value, where the variable value exceeds 1.5 times the difference between the 75% and 25%.