This Flower Parts Diagram science diagram depicts the various parts of flowers. Flowers are a plant's reproductive organ. They reproduce and serve as a food source for other living organisms. They are an abundant source of nectar. A complete flower comprises sepals, petals, stamens, and pistils. An incomplete flower lacks one or multiple of these structures. This Flower Parts Diagram science is a well-labeled and simple flower diagram for your convenience. Plants differ in the number of petals, sepals, stamens, and pistils. The presence of these elements determines whether the flower is complete or incomplete.