In early May, apple trees are covered in apple blossoms. In order for the blossoms to become apples, they must be cross-pollinated. This means that the pollen must travel from one flower to another before fertilization can occur. Bees are responsible for this essential task.
Pollen is made by the stamens of the blossom. When bees travel from blossom to blossom, they collect pollen and drop it from the stamens of one blossom onto the pistils of another blossom. The pollen travels from the sticky tips of the pistils—called the stigma—down a long tube called the “style,” and enters the ovary. It is at this point that fertilization occurs and ovules within the ovary become apple seeds.
After the seeds develop, the petals from the blossoms fall off. Next, the ovary starts growing. The ovary is surrounded by a thin protective layer. This layer eventually becomes the core line, or apple core. The outer layer surrounding the ovary becomes the exocarp, or the eating part of the apple. The calyx, stamens, and pistils become the dry, hairy part at the bottom of the apple.