Pistil

Definition

The pistil is the female reproductive part of a flower, typically consisting of an ovary, style, and stigma. It plays a crucial role in plant reproduction by facilitating fertilization, as it houses the ovules that develop into seeds after pollination. The structure of the pistil varies across different plant species, influencing how they interact with pollinators and their overall reproductive success.

5 Must Know Facts For Your Next Test

1. The number of pistils in a flower can vary widely; some flowers have a single pistil while others have multiple pistils fused together.
2. Pollination occurs when pollen from the male parts of a flower (stamens) reaches the stigma of the pistil, leading to fertilization.
3. After successful fertilization, the ovary develops into fruit which encases the seeds, ensuring their protection and aiding in dispersal.
4. The pistil can be classified into simple and compound types, where a simple pistil has one ovary and a compound pistil has two or more ovaries fused together.
5. Different flower shapes and colors can influence pollinator attraction, affecting how efficiently pollen is transferred to the pistil.

Review Questions

• How does the structure of the pistil contribute to its function in plant reproduction?
  • The structure of the pistil is specifically designed to facilitate fertilization. The stigma's sticky surface captures pollen grains, while the style provides a pathway for pollen tubes to grow down to the ovary. This design ensures that once pollination occurs, pollen can reach the ovules housed within the ovary, allowing for successful fertilization and seed development.
• Compare and contrast simple and compound pistils in terms of their structure and reproductive roles.
  • Simple pistils consist of a single ovary, while compound pistils are made up of multiple ovaries that are often fused together. In terms of reproductive roles, both types allow for fertilization and seed development, but compound pistils can produce multiple seeds from separate ovaries within a single flower. This structural difference influences fruit formation and can impact seed dispersal strategies.
• Evaluate how variations in pistil structure across different plant species affect their interactions with pollinators and overall reproductive success.
  • Variations in pistil structure can greatly influence how effectively a plant attracts pollinators and achieves reproduction. For example, flowers with longer styles may be adapted for specific pollinators that can reach deeper parts of the flower, thus enhancing pollen transfer efficiency. Conversely, plants with wide, open stigmas might attract a broader range of pollinators. These structural adaptations can determine how successful a plant is in its reproductive efforts by influencing both pollination rates and genetic diversity through cross-pollination.

Related terms

Stigma:

The part of the pistil that receives pollen during fertilization; it is often sticky or feathery to capture pollen grains effectively.

Ovary:

The swollen base of the pistil that contains the ovules; after fertilization, it develops into the fruit of the plant.

Style:

The slender column of tissue that connects the stigma to the ovary; it supports the stigma and provides a pathway for pollen tubes to grow toward the ovules.