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Author Topic: Why does a sunflower follows direction of the sun?  (Read 4178 times)

Offline omid

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Omid heard a story from granny when omid was a kid and she used to tell omid that actually sunflower was a girl and fall in love with the sun and then she marries the sun and after some time she had some argument cz of which sun threw her out of his house she was so much in love with the sun that she turned into a flower and till today follow the direction of the sun.

omid knows that this is not true so want to know the real truth

can somebody help plz ???
« Last Edit: 04/03/2010 15:52:26 by omid »


 

Offline Jessica H

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Why does a sunflower follows direction of the sun?
« Reply #1 on: 08/03/2010 04:46:23 »
It is odd that the flower tracks the sun; it'd be more logical if it were the photosynthesizing parts, the leaves, only.  I've heard it might have something to do with attracting pollinators- a warm nectar is more appealing to insects.

The physics of this confuses me, though.  Is there actually more energy in the nectar if it's warm?  Like a cup of hot cocoa makes you feel warmer, but then again it doesn't have more calories than cold chocolate milk. 
 

Offline Jessica H

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Why does a sunflower follows direction of the sun?
« Reply #2 on: 09/03/2010 01:35:47 »
That would make sense that they would stop tracking the sun once they were pollinated.  If the goal is to attract pollinators, there's no reason to keep going as the fruit matures.

I like the "odoriferous" nectar theory. (And I learned a new word today :))
 

Offline Jessica H

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Why does a sunflower follows direction of the sun?
« Reply #3 on: 12/03/2010 05:45:18 »
I found an article about the theory that heliotropism co-evolved with pollinators.  This study was in alpine plants, but the concept is the same.   
http://www.jstor.org/pss/1552282
 

Offline Jessica H

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Why does a sunflower follows direction of the sun?
« Reply #4 on: 12/03/2010 05:58:25 »
Correction- not the same in sunflowers! 

From the gardening forums I read, too, that they are only heliotropic in the bud stage. Somehow it speeds bud development.
 
 

The Naked Scientists Forum

Why does a sunflower follows direction of the sun?
« Reply #4 on: 12/03/2010 05:58:25 »

 

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