Pollen must fertilize an ovule to produce a viable seed. This process is called pollination, and is often aided by animals like bees , which fly from flower to flower collecting sweet nectar. As they visit flowers, they spread pollen around, depositing it on some stigmas. After fertilization, the ovule develops into a seed in the ovary. Some plants have both male and female flowers, while other have males on one plant and females on another.
Complete flowers have stamens , a pistil , petals , and sepals .
Incomplete flowers lack one of these parts. Without our visitors' support, Enchanted Learning would soon be off-line.