What Part of a Flower Contains the Stigma & the Style?

The stigma and the style are female reproductive parts of a flower.

For plants to reproduce they must be able to produce seeds. Flowers contain the male and female reproductive organs that enable seed production. The stigma and style are two of the female reproductive parts of flowering plants. These parts are essential as they allow pollen, carried to the flower by pollinating insects, such as bees and butterflies, to travel into the ovary, thus fertilizing the flower and resulting in seed formation.

Location

The stigma, style and ovary make up the pistil, which is located in the center of the flower. A flower often will contain more than one pistil. When pistils fuse together, the resulting group of pistils is known as a carpal.

Function

The style is a tube that connects the stigma to the ovary. During their travels from flower to flower, insects collect the pollen that is produced by the anthers, which are the male reproductive parts of the flower, and transfer it to the stigma. This pollen travels down the style to the ovary to complete the fertilization. The ovary contains one or more ovules that develop into seeds after fertilization, and the ovary then becomes the fruit of the plant.

Characteristics

The stigma is sticky to aid in the collection of pollen. It consists of a protruding nodule on the end of the style with an opening to allow the pollen to enter. The style is stem-like in appearance, but is larger in diameter than the anther filaments around it. The stigma and style vary in color based on the plant variety, but they often are white or yellow.

Self-pollination

Some flowering plants are capable of fertilizing themselves, but many plants have measures in place that prevent this from happening, which encourages diversity in the plant. The mechanisms used to prevent self-pollination include the development of the stigma and stamen that are too far apart to touch easily, carpels and stamens that mature at different times, and chemical recognition in which the stigma recognizes and rejects pollen from the same plant. A few flowering plants do not contain male and female organs in the same flower, making self-pollination impossible.

References

• Adventures in Field Botany: Flower Anatomy
• University of Illinois Extension: Plant Parts- Flowers
• Andromeda Botanic Gardens: Flower Structure and Function
• Serendip; The Sexuality of Flowers; Sara Davis; 1997