Fig. 1. Five different two-dimensional flower morphs tested in Experiment 1. (A) `No transparency' paper flowers, whose surfaces are covered with acetate film cut to their exact shape, to control for fine texture. (B) `Transparency' flowers covered with a square (9 cmx9 cm) sheet of acetate film. Arrows and brackets indicate a priori comparisons: (I) `half lobes vs medium disks' compares flowers that have different surface area but the same edge-to-center distances. (II) `Half lobes vs small disks' compares flowers with similar surface area but different edge-to-center distances. Note: all flowers have accessible nectaries at their centers.