Flowers that are pollinated by the wind usually have smaller petals and sepals than flowers that are pollinated by insects or animals.

Why are small petals and sepals an advantage to these flowers?

Small petals and sepals an advantage to these flowers: The flower petals and sepals are adaptations that attract pollinators. Flowers that are 'pollinated by the wind' mostly have smaller sepals and petals as they do not have the need of attracting pollinators like insects, birds and bats. In addition, it is possible that sepals and petals get in the track of pollen which might fly around in the wind. Also, it may "inhibit pollen" from "sticking" to the stigma. Hence, wind pollinating plants comprise of small sepals and petals.