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

Flower traits, such as flower size or color changes, can act honest signals indicating greater rewards nectar; however, nothing is known about shelter-rewarding systems. Large flowers of Royal irises offer overnight shelter a reward to Eucera bees. A black patch might signal the entrance tunnel (shelter) and, together with size, these signals. We hypothesize that larger and patches indicate tunnels, tunnels will increase pollinator visits, enhancing plants’ reproductive success. measured seven species in controlled environment two from three natural populations varying size. Fruit seed sets were assessed populations. found positive correlation between flower, volume, suggesting signals, both under conditions wild. However, populations, this relationship its effect on fitness was population-specific. increased YER I. petrana, interactions flower/patch atropurpurea NET This suggests honesty positively selected study supports hypothesis pollinator-mediated selection leads signaling advertisement.