Broccoli, a biennial member of the cruciferous family of vegetables, along with cabbage and Brussels sprouts, relies on sexual reproduction just like other fruits and vegetables do.
Parts of a broccoli flower
If you look closely at broccoli that's ready to harvest, you will see a tightly packed head with a rough, lumpy surface and thick compact stems--the familiar look of broccoli that is harvested and sold in stores. The lumpy surface contains thousand of immature flower buds. When the broccoli flowers open, they have petals, stamen, stigma, pistle, ovule and pollen.
Pollen contains male gametes (sperm), and the ovule contains female gametes (eggs). The two have to be brought together for pollination to take place. Broccoli relies on pollination to reproduce just like other fruits and vegetables do. Pollination takes place when insects or birds attracted by the scent and color of the flowers feed off nectar on the stigma or around the base of the ovule. The insects transfer pollen from the stamens to the stigma, where it fertilizes the female gametes in the ovule.
Gestation to harvest
As the newly fertilized seeds inside the ovule grow, the ovule lengthens into a pod where the seeds will mature after several weeks. Broccoli plants produce dozens of pods, each with eight to 10 small, hard, dark brown seeds inside. The seeds are about the size and shape of brown mustard seeds and have a pleasant peppery taste.