A stamen is part of the reproductive system of a flower. Stamens are usually referred to as the male parts of the flower, because they generate pollen which is used to fertilize the pistils, commonly known as the female parts, of other flowers. Once fertilized, the pistil will develop a fruit which has the potential to develop into a new plant. Many people are familiar with stamens and the pollen they carry because they tend to be prominent structures in a flower, as the flower wants to ensure that its pollen will spread as much as possible, thereby perpetuating its genetic material and the survival of the species as a whole.
When one looks at a flower, the stamens are located in the middle, between the petals. In most cases, the stamens surround the pistil of the flower, and the plant uses a variety of techniques to prevent self-pollination, in which its own pollen fertilizes the pistil. Some plants produce stamens and pistils on different flowers, or different plants, to make self-fertilization even less likely.
Each stamen has two parts: the anther and the filament. The anther is a small sac which holds the pollen, while the filament is a thread which holds the anther up. Anthers typically have two lobes, and they can be quite large. The filaments vary in length, a technique used to deal with self-fertilization issues. Some plants have especially long or short filaments to prevent contact between the pistil and the stamen. Others may mature their pistils and stamens at different times.
In some cases, an area known as a nectary can be found at the base of the stamen. This area includes a sweet liquid which is designed as an incentive and a reward to pollinators such as bees, butterflies, and birds. These animals alight on the flower to access the nectar, and collect pollen along the way, transferring that pollen to other plants when they access their nectaries.
The number of stamens in a flower can vary. Sometimes, a flower has as many stamens as it has petals, while others may generate many more. Botanists may sometimes classify and distinguish between different groups of flowers on the basis of how many stamens they have, since stamens are easy to identify and count. Some people have noted that stamens are particularly prominent in some types of flowers, and brushing up against the stamen may result in a stain from the pollen; these plants may have their stamens clipped when their flowers are cut for sale.