Krampf
Experiment of the Week - Smell the Flowers - 3/27/09
http://www.krampf.com
The
idea for this week's experiment comes from my wife, Nancy. I was
sitting here at the computer, trying to decide what to write about when
Nancy made a comment about how good the flowers on the table
smelled.
Nancy loves flowers, and always has lots of them around the
house.
That one whiff and this week's newsletter practically wrote itself.
If
you are lucky enough to have flowers around your house, take a few
minutes and smell them. If you don't have flowers around the
house,
you should be able to find a variety of flowers at your local grocery,
hardware store, or nursery. Once you are surrounded by the
flowers,
take the time to sniff them, one by one. Keep track of your
observations (sniffservations?) What did you notice?
You
probably found that if you smell several different examples of the same
kind of flower, they all smell pretty much the same. You also
probably
found that different varieties of flowers have very different
smells.
Why?
For
that matter, why do flowers smell at all? What purpose does the
smell
serve? To answer that, think about what purpose the flower
serves.
The purpose of a flower is to get pollen cells from one plant to
connect with the egg cells of another plant of the same species, in
order to produce fertile seeds to make more plants.
The
trick is to move the pollen from one plant to another. Different
plants have different ways of doing that. Some rely on wind to
blow
the pollen from flower to flower. Others rely on water, but the
vast
majority of plants count on animals to do the work. Spend some
time
watching flowers in a garden, and you will see a wide variety of bees,
butterflies, flies, beetles, hummingbirds, and other creatures busily
pollinating the flowers.
How
wonderful that those dedicated creatures spend their lives tirelessly
helping the plants with no thought of payment or reward! Think
again!
That is about as likely as me coming over and begging for the
privileged of mowing your lawn, and you can ask my Mom how I feel about
mowing lawns.
OK,
then why do those animals spend their time carrying pollen from flower
to flower? Bribes! The flowers produce drops of sweet
nectar as bait
to convince the bees, butterflies, and other creatures to visit.
The
pollen is strategically placed so that in order to get to the nectar,
the creature can't avoid bumping into some of the sticky pollen.
It
also bumps into the stigma, where pollen that is already on the little
critter can stick to pollinate the flower.
Now
that may all be interesting, but what does it have to do with the smell
of the flowers? That smell is a way of advertising nectar,
letting
creatures know that there is good stuff available, but it is also a way
of selectively advertising it. Rose pollen is no good for a
gardenia.
Gardenia pollen is no good for a dandelion.
Each
flower needs pollen from a similar plant, so they have developed
different colors, shapes, and smells to attract different
pollinators.
Bees, beetles, butterflies, and hummingbirds all have their favorites,
which they visit more frequently. Having a unique color, shape or
smell makes it more likely that a flower will get pollen from another
of the same species.
Some
flowers have smells that are not nice at all (at least to us.) A
good
example is Rafflesia, one of the world's largest flowers. Its
flowers
smell like rotten meat. Why? What self respecting animal
would be
attracted to rotten meat? Flies! What smells horrible to us
smells
like a wonderful meal to the flies. That greatly increases the
probability that a fly will bring pollen from another Rafflesia,
instead of some stinky old rose or gardenia.
The
same idea works with people. Instead of the smell of flowers and
carrying pollen, try the smell of fresh baked cookies and taking out
the trash. It works on me every time.