Principal components analysis score plot (Fig. 1a, left) and loading plot (Fig. 1b, right) of characters and species in Table 1. Most heavily weighted characters labeled and indicated with red arrows in loading plot. Red triangles = S. jobsonii; black crosses = S. eburneum; purple circles = S. diversiflorum; yellow diamonds = S. watneyi. Labels for loading plot are as follows: A Apical leaf depth of lobing B Basal leaf width C Basal leaf depth of lobing D Stem prickle length E Hermaphrodite calyx lobe length F Staminate calyx lobe length G Basal leaf length H Male corolla diameter I Hermaphrodite corolla diameter J Apical leaf length K Apical leaf surface area L Petiole length M Internode length N Apical leaf width O Plant height P Fruiting pedicel length Q Seed length.