MadSci Network: Botany

Re: Why are red flowers so rare?

Date: Sat Aug 18 01:34:33 2001
Posted By: David Hershey, Faculty, Botany, NA
Area of science: Botany
ID: 996226909.Bt

You cannot readily extrapolate from sea anemones to plants because their 
pigments and use of light are different. Unlike sea anemones, plants are 
designed to absorb most visible light for photosynthesis. 

You have not provided solid evidence that red flowers are rare or absent 
especially at high altitudes, and the previous answer noted that at least some 
red flowers occurred at high altitudes. The alpine flower website cited in the 
references has a number of pink or reddish flowers. Flower coloration is to 
attract animals as pollinators. Red flowers seem especially attractive to 
birds, particularly hummingbirds, so the number of red flowered species may 
have some relationship to the number of bird pollinated species.

Your idea that reflecting just most of the red wavelengths, but not green, 
yellow, blue, orange, etc. would protect the plant is not logical. White 
flowers actually would reflect the most colors of light but white flowers are 
common at all altitudes. 

Plants do have accessory pigments, such as cartenoids, that are thought to help 
protect chlorophyll in leaves. Anthocyanins, that provide flower colors, 
protect from UV-B radiation. Therefore, any heavily pigmented flower may 
provide greater protection from UV-B at high altitudes. Plants also contain 
flavones and flavonols that absorb UV radiation and are colorless to human 
vision. However, colored petals do not have light-sensitive
chlorophyll to protect so anthocyanins main function is apparently for 
coloration to attract pollinators.


Meeuse, B. and Morris, S. 1984. The Sex Life of Flowers. New York: Facts On 
File. Alpine Flowers (link defunct as of 8/22/2006).

Alpin floral collection 

How Carotenoids Protect Chlorophyll
Why are some leaves permanently red or yellow? (link defunct as of 8/22/2006)

Current Queue | Current Queue for Botany | Botany archives

Try the links in the MadSci Library for more information on Botany.

MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci

MadSci Network,
© 1995-2001. All rights reserved.