Flower Size as an Honest Signal in Royal Irises ( Section , Iridaceae).

Flower traits, such as flower size or color changes, can act as honest signals indicating greater rewards such as nectar; however, nothing is known about shelter-rewarding systems. Large flowers of Royal irises offer overnight shelter as a reward to bees. A black patch might signal the entrance to the tunnel (shelter) and, together with the flower size, these might act as honest signals.