Phene values of maize root phenotypes with comparable FD (a) and convex hull volume (b). The heat map shows values of the traits obtained by dividing the values with maximum value of respective traits. The visualization of the phenotypes with similar FD and similar convex hull volume is presented in (c) and (d), respectively. Phenotypes a1-a8 have similar FD; phenotypes b1-b8 have similar convex hull volume. PR: primary root; SR: seminal root; NR: nodal root; LRBD: lateral root branching density; Len: axial root length; Lat.Len: lateral root length; #: number of axial roots; FD: fractal dimension.