It's Getting Hot out Here
It’s getting hot in the vineyard - and it’s not just from the sunshine. Favored for cultivation, hermaphroditic grapevines contain both male and female reproductive organs, allowing them to self-pollinate.
In short - during fertilization, the calyptra, a structure protecting the undeveloped grape cell, sheds to free the pollen-producing male stamens. Landing on the centralized female stigma, the pollen is delivered to the ovary through a tube-like structure called the style. Upon completing its journey to the ovary, the pollen performs fertilization and the ovule develops into a grape seed. Just like that, flowering is underway.
Welcome to Plant Physiology 101.