Why do wind-pollinated flowers often have small petals or no petals?

Wind-pollinated flowers, or anemophilous flowers, often have small or absent petals because they do not require the showy structures used to attract animal pollinators.12

In contrast to flowers that rely on insects or birds, wind-pollinated species are devoid of attractants and rewards such as fragrance, nectar, and colorful petals. These features are evolutionary adaptations specifically designed to lure pollinators; since wind-pollinated plants rely on air currents to disperse pollen, these energy-intensive structures provide no reproductive advantage.13

Instead, wind-pollinated flowers prioritize features that facilitate the release and capture of pollen from the air. They often feature:

• Inconspicuous perianths: The floral parts are reduced to minimize physical barriers to wind.2
• Exposed reproductive organs: Stamens and stigmas are often positioned to move easily in the breeze, allowing pollen to be shaken out or caught more effectively.1
• Specialized stigmas: Stigmas are frequently long, branched, or lobed to maximize the surface area available for trapping wind-borne pollen.12

By eliminating unnecessary petals, these plants can allocate resources toward producing the massive quantities of pollen required to compensate for the inefficiency of wind dispersal.1