Stamen

Stamen

Stamens of an Amaryllis flower

The stamen is the pollen-producing reproductive organ of a flower. Collectively, the stamens form the androecium of a flower. The stamen typically consists of a stalk called the filament and an anther, which contains microsporangia.

Structure

Diagram of a stamen

A typical stamen consists of two main parts:

• Filament: The filament is a slender stalk that supports the anther. It positions the anther in a way that facilitates the transfer of pollen to the pistil or to pollinators.

• Anther: The anther is the part of the stamen where pollen is produced. It usually consists of two lobes, each containing two microsporangia. The microsporangia are the sites of pollen development.

Function

The primary function of the stamen is to produce and release pollen. Pollen grains contain the male gametes necessary for fertilization in plants. During the process of pollination, pollen is transferred from the anther to the stigma of a flower, leading to fertilization and the production of seeds.

Variations

Stamens of a Hippeastrum flower

Stamens can vary greatly in size, shape, and number among different plant species. Some flowers have a single stamen, while others may have numerous stamens. The arrangement and morphology of stamens can be important for the identification of plant species.

Development

Stamens develop from the floral meristem and are considered modified leaves. During development, the stamen primordia differentiate into the filament and anther. The anther undergoes meiosis to produce haploid pollen grains.

Pollination

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Close-up of Lilium 'Stargazer' showing stamens

Pollination is the process by which pollen is transferred from the anther to the stigma. This can occur through various mechanisms, including wind, water, and animal pollinators such as insects and birds. The structure and position of stamens can influence the method of pollination.

Related Structures

Diagram of a mature flower showing stamens

• Pistil: The female reproductive part of a flower, consisting of the stigma, style, and ovary.
• Petal: Often colorful parts of a flower that attract pollinators.
• Sepal: Protective leaf-like structures that enclose the flower bud.

Examples

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Anther of a Lilium flower

• Lilium: The lily flower has prominent stamens with large anthers that are often visible and produce abundant pollen.
• Hippeastrum: Known for its large, showy flowers with long stamens.
• Phalaenopsis: Orchids with unique stamen structures adapted for specific pollinators.

Related Pages

• Pollination
• Flower
• Reproduction in plants

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Stipe of a Phalaenopsis orchid

Gallery

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  Anther of a Penta flower