Sunflowers are one of our favorite flowers, and we have lots of them blooming this year. They are one of those flowers that just seem to cheer you up with their bright yellow color and, well, sunny disposition and looks. It's fun to watch them unfold, as the pucker faced sour pusses
slowly, teasingly, almost reluctantly reveal their beauty.
They look coy as they play a shy game of peek-a-boo
and then suddenly they are all bold, brazen beauty, shining forth in all their golden glory.
We have some impressive giants this year:
I called this one the sunflower fountain:
The birds are loving them right now. Every time I go outside there are numerous goldfinches in the sunflowers and I love watching them eat,
especially their up-side-down tricks.
The bees and butterflies love them too, such as this one:
I have a long row of giant sunflowers along my back deck, and a lineup of the shorter, branching sorayas along a flower bed in the back yard, and some scattered surprises that have popped up here and there on their own. It's so neat and tidy how they all face east. Sunflowers are heliotropic, turning their heads to follow the sun, until the blooms open and then they stay facing east to get the most sun.
I recently had the pleasure of meeting Jennifer at the FCL conference, and I was delighted to read her garden post featuring sunflowers. She wrote about the patterns of the spirals and how Fibonacci numbers are present in the seed patterns. I'd been taking pictures of the spirals, so I was greatly intrigued by this mathematical information. Apparently the seeds are arranged in spiral patterns as that is the most efficient way of filling the circular space of the flower head. The seeds are placed at precise angles, with spirals going both clockwise and counter clockwise. The number of spirals is always two consecutive numbers in the Fibonacci sequence. There are typically 34 spirals in one direction and 55 going the opposite way. A very large sunflower may have 89 and 144 spirals respectively ( I think my big ones do, but it was hard to count them from the picture taken so far away). The spirals are easiest to see and count when the flower is just opening, or after all the florets have fallen off and just the seeds remain.
I was totally intrigued by all of this information, especially after recently hearing Macbeth's talk on using nature to study math. The wonderful mathematical intricacies of order shown in God's design of these sunflowers fascinated me, and I wanted to count the spirals. It took me a little while to figure it out, and I wanted to draw the spirals to help me count and see the two directions. My dear husband who is a mathematics loving scientist, came along and set about to do it proper. Michael took one of my photographs and very precisely drew in the spirals so they can easily be seen and counted. Here is the original picture:
Here you can see the 34 counterclockwise spirals in blue:
Here you can see the 55 clockwise spirals in purple:
Here are both together, so you can see the intersecting patterns:
He also put the pictures into a handy pdf so you can see them in higher resolution or print them out for your students: Download Sunflower More information can be found in the Wiki article Jenn linked to, and there is also more info here: Flower Patterns and Fibonacci Numbers. Thanks so much, Jenn! And thank you Dr. K!