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Flowers are a group of highly specialized structures used in the sexual reproduction of angiosperms. Every aspect of a flower (appearance, scent, pollen, nectar, etc.) is adapted for efficient pollination to produce seeds.
Flowers are made up of four basic parts (floral series): the calyx, corolla, androecium, and gynoecium. The androecium and gynoecium are the two fertile floral series (andro: "male", gyno: "female", ecium: "home"). The calyx and corolla, collectively called the perianth, are not directly involved in sexual reproduction. All four floral series are derived from highly specialized leaves.

Two sterile floral series (Perianth):


collective term for sepals, the outermost part of a flower that protects the flower bud until it blooms.


collective term for petals, whose main function is to attract pollinators: usually brightly colored.
Sepals are usually green, leaflike and relatively rough.

In some flowers, sepals and petals can look similar.

When sepals and petals are similar in size, shape and color, they are called tepals.

Two fertile floral series:

Androecium collective term for stamens, each of which includes a filament and anther. It is the male part of a flower that produces pollen.
Gynoecium collective term for pistils (carpels), each of which includes a stigma, style and ovary. It is the female part of a flower that produces eggs (ovules). Ovules can develop into seeds. Fruits develop from the mature ovary.

Simple pistil:

a pistil formed by a single carpel.

Compound pistils:

a pistil formed by fusing two or more carpels.

Other terms:


the stem that supports a solitary flower or an inflorescence.


the stalklike stem that supports an individual flower in an inflorescence.


the enlarged end of a flower-bearing stem where the various flower parts attach.

Flower dissections at the information desk

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