Why Are Flowers Brightly Colored?

The lovely variety of colors seen in flowers serves a vital purpose to the plants.

Flowers are one of nature's many gifts of beauty, adding visual appeal to home gardens, city parks, and even bouquets in the home. Their amazingly variety of colors possess the ability to please the human eye and brighten up a room or garden. Those colors also serve an essential purpose as they help maintain the life cycles of insects, birds and the flowers themselves.

Features

Plant pigments called anthocyanidins are responsible for the bright colors in a flower. People perceive the color of a flower when light rays--whether from the sun or from an indoor bulb--hit anthocyanidin-pigmented plant cells and reflect back at the human eye, states Dr. Leonard Perry of the University of Vermont. However, the brilliant colors of flower petals have other, smaller eyes fixed on them--and this is the primary reason flowers have bright color.

Function

Flying insects and birds are visually attracted to the light reflecting from a flower's anthocyanidin pigmentation, and move in to collect pollen or nectar. In this way, brightly colored flowers function to provide flying creatures with valuable pollen, while in the process ensuring that extra pollen is delivered to other flowers. This helps flowering plants cross-pollinate and expand their population according to Tennessee's Department of Energy and Conservation (TDEC).

Types

Flowers are well known for coming in nearly every conceivable color--and this too has a purpose beyond simple aesthetic appeal. Different insects and birds are attracted to different types of plant pigmentation according to TDEC. For example, bees show an affinity for flowers that are yellow, blue or violet, but they're blind to the color red. Birds, however, are attracted to red flower blossoms, which tend to appear on fruit-bearing plants. Birds that feed on fruit from flowering plants spread seeds through their droppings, providing new flowers with places to grow.

Time Frame

The pigment of some flowers changes over time according to Perry. Lungworts and forget-me-nots, for instance, change from pink to blue. This unique pigment shift occurs as the flowering plants age, and provides a visual cue to flying insects that the flowers are past their pollination prime.

Considerations

Insect attacks or infestations, droughts, periods of too little sunlight, and too much water can alter the color of flowers. Plants with normally brilliant colored flowers will grow sick under some of these conditions and it will result in pale or "washed out" pigmentation. Owners of pigmented plants should provide them with adequate light, nutrition and water, and keep them free of damaging insects such as ants and aphids.

References

• UVM.edu: The How and Why of Flower Color
• Tennessee.gov: The Meaning of Flowers

Resources

• SIL.SI.edu: Galaxy of Images (Flower Color)