The ovule of a flower is also known as the megasporangium which arises from the placenta. The arrangements of ovules in the ovary are called placentation. The ovule is attached to the inner surface of the ovary by a stalk called as the funicle or funniculous. The point of this attachment is known as the hilum. The ovule is small oval structure which has a central mass of tissue called as the nucellus. This nucellus remains surrounded by a one or two protective layer known as the integument. The integuments surrounds the nucellus except at the apex which known as the micropyle.