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These structures are often the parts that make flowers attractive to humans, but also to other animals that may serve as pollinators.

Petals: The petals are often the "showy" or colorful parts of the flower.

The anther occurs at the end of the filament.

A typical stamen has two distinct regions.

Stamens: The microsporophylls (microsporangium-bearing leaves) or "male" parts of a flower.

A fruit develops from the ovary of a flower, and the seeds develop from the ovules. Flowering plants keep their seeds in a container, the fruit. In fact, the ovary is what gives angiosperms (Greek, angeion + sperma = vessel + seed) their name.

The ovary, the portion of the carpel that contains the ovules, or the structures that will become seeds following fertilization.

The style, a stalk-like structure that elevates the stigma.

The stigma, a specialized surface on which pollen grains land and germinate.

A flower may have one carpel, two or more distinct carpels (i.e., carpels that are not fused to one another), or two or more carpels fused into a single structure.

Carpels : The megasporophylls (megasporangium-bearing leaves) or "female" parts of a flower.

These whorls are as follows, listed from innermost (or uppermost) to outermost (or lowermost): The "ideal" or "stereotypical" flower is made up of four levels, or whorls, of structures attached to an axis called a receptacle. Overview of floral structure & terminology Thus, except in certain unusual circumstances (for example, amber inclusions, Cretaceous charcoalified floras), flowers tend to be rare in fossil deposits.

Flowers are ephemeral and often delicate.

Variations in flower structure are very important in the identification and classification of modern angiosperms. ( Read more about pollination here.) Flowers may have either carpels (ovule-producing structures) or stamens (pollen-producing structures), or both carpels and stamens. Wind-pollinated flowers tend to be inconspicuous, without a lot of unnecessary structures that might get in the way of pollen grains transported on air currents.

Animal-pollinated flowers are often modified in ways that help them to attract and interact with their pollinators, such as having bright colors, patterns, rewards (i.e., nectariferous tissue that produces nectar), and enticing fragrances. Furthermore, the whole flower can be considered a type of simple strobilus, or cone, because it is a terminal reproductive unit consisting of a central axis that bears sporophylls.įlowers vary in the numbers and arrangements of carpels, stamens, petals, and sepals that they possess, as well as in other attributes. The carpels and stamens are thus sporophylls, or fertile leaves (strictly, sporangium-bearing leaves). In a typical flower, both the fertile and sterile structures are interpreted as leaf homologues (modified leaves). Sterile structures ( petals and sepals) that vary in appearance from green and leaf-like to brightly colored may occur below the fertile structures. Many flowers have two types of fertile structures, carpels that enclose ovules (immature seeds) and stamens that make pollen. The flower is the reproductive unit of an angiosperm, meaning that it is the location in which the key processes of sexual reproduction ( meiosis and fertilization) are carried out.