Crossing polygon indicating results from interpopulation crossings. The color of the circles corresponds to the crossing groups inferred by the crossing experiment. Names of the populations correspond to the codes in Table 1. A double line indicates that the crossings were done in both directions (♀ pop. X with ♂ pop. Y as well as ♂ pop X with ♀pop. Y), whereas unique single line means that only one direction of the cross was conducted. The width of the lines is proportional to the number of flowers tested for this crossing. The dashed lines refer to incompatible crossings, whereas solid lines indicate compatible crossings leading to the formation of seeds.