Can You Capture Fragrance?

This week you have an experiment to do, but before I tell you what that experiment will be, let’s discuss flowers and how they attract pollinators.

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Flowers are a special advertisement for plants to attract help for pollinating services.  You see, flowers contain both nectar, a sweet sugar watery treat, and pollen, a protein and fat filled morsel.  Pollinators are well aware of the offerings flowers contain within their bright and showy petals.  Most pollinators are after the nectar, and others will take advantage of both the nectar and pollen.  Bees use pollen to feed their young, and nectar is also used as a food source.  The question is, what is a flower doing to attract pollinators to them in the first place?

Let’s begin with color.  Have you ever noticed that flowers are never dull and boring, blending in with the surroundings? Flowers are bright and showy.  Some are small, but still very visible due to color.  Pollinators see colors differently than each other, and better than we do.  Pollinators can see in the UV range, and the UV pattern they see within every flower shows a nectar map.  The nectar map is bright when the flower has lots of nectar, and dull when the nectar supply is low.  Pollinators will pass the flowers with dull nectar maps, because they know the nectar supply isn’t enough for them.

Løvetann (Taraxacum sect. Ruderalia;  T. officinale).  Sammensatt bilde som viser blomsterkorg og bladverk i ultrafiolett (UV) og i synlig lys.The left shows a Dandelion in UV, and the right is how we see it…WOW!

Another way flowers attract pollinators is by fragrance, which is the smell the flower gives off at different times of the day, depending on the pollinator that visits that flower.  Flowers pollinated by nocturnal pollinators (night flying) will release more fragrance in the evening hours, while flowers pollinated by day flying pollinators will release more fragrance at different times of the day.   This fragrance is detected by pollinators via antennae, and in the case of the bat, it’s nose.   Here’s an interesting fact, hummingbirds cannot smell very well at all, but they have excellent eye sight.

Now that we know how flowers attract pollinators, let’s do an experiment.  Begin by pulling one or two petals off off three different kinds of flowers.  Then track down some containers with lids. Preferably clear containers.

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Place the petals inside the containers and put the lids on.

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Now find a sunny window to place them in, and let them bathe in the sunlight for some time, and then smell.  Put the lid back on and smell them again in the evening.  Is there a difference in how strong the scent is between the two times you chose to smell them? Changes in sunlight tell flowers how much fragrance to release.

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Enjoy your assignment, and don’t forget to stop and look at all the pollinators during your venture out to collect petals!

 

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