What is Flower Structure?

A flower is the reproductive structure of angiosperms. Flowers differ in color, scent, and shape, yet many share common reproductive parts.

What parts make up a flower?

In a typical flower, sepals protect the bud, while petals may help attract pollinators. Anthers on the stamen produce pollen. The stigma of the pistil receives pollen; the style allows a pollen tube to grow, and the ovary contains ovules. Not every flower has all these parts: unisexual flowers and inconspicuous wind-pollinated flowers also occur. The receptacle and flower stalk support reproductive structures. Structural diversity is related to pollination, but no single color or scent guarantees a particular pollinator.

From pollination to seed

Pollination is the transfer of pollen from an anther to a stigma of the same or another flower. Under suitable conditions, a pollen tube grows and male reproductive cells can reach an ovule. After fertilization, the ovule develops into a seed and, in most angiosperms, the ovary develops into a fruit. Timing and details vary among plant groups. Some plants can self-fertilize; others rely more on cross-pollination, which can increase genetic diversity. To understand flower structure, it is useful to examine not only showy petals but also where pollen is produced and received.