How can both wind and insects pollinate gnetophytes?

Gnetophytes can be pollinated by both wind and insects because they utilize a specialized reproductive mechanism involving a pollination drop.1

Just before pollination, a viscous, sugar-rich solution is extruded through the opening of the ovule (the micropyle), forming a droplet at the tip of the integument. This drop serves two distinct functions:1

• Insect Pollination: The high sugar content of the pollination drop acts as a reward that attracts insects to the plant.1
• Wind Pollination: When pollen grains—whether transported by wind or insects—make contact with this sticky droplet, the subsequent drying of the solution pulls the grains inward through the integument, depositing them onto the nucellus where they can germinate.1

This dual-purpose mechanism allows gnetophytes to effectively capture pollen regardless of whether it arrives via air currents or animal visitors.1