Thursday, December 29, 2011


Sunflower.  Source.


I have learned that a typical week for me involves at least one instance of surprise interest in a topic I had previously found mundane.  A week or so ago, this proved to be the sunflower.  I have not heavily researched this topic, but I stumbled across a few tidbits of information I hope we shall all find interesting.

One surprise to me was that the native sunflower of North America is a perennial species [comes up year after year], unlike the farmed varieties which may behave more like an annual [dies outright every winter].  As a result, considerable interest has been generated recently in producing a hybrid of the high-yield annuals with the perennial behaviour of the native varieties.  Since sunflower oil may be used as both a food product and a source for biodiesel, it would be wonderful to have a perennial oil crop.  Eliminating the fuel/energy requirements for planting such crops every year makes for a more sustainable future, and makes the farming process more efficient overall.  While I would prefer to see switchgrass used for fuel, I can certainly appreciate having a perennial food crop.

Graphical representation of sunflower floret placement.  Source.
While I have little to no understanding of the mathematical significance of such a thing, the way in which the florets/seeds of the sunflower arrange themselves is a form of the Fibonacci spiral and the periodic angle of placement is related to the golden ratio.  I have no idea why, but Wikipedia states that it is 55/144 of a circular angle, where 55 and 144 are Fibonacci numbers.  Huzzah, I suppose.  Regardless what it means, it certainly looks to be a very efficient spatial arrangement (no doubt perfected with a genetic algorithm), and is rather hypnotic.  I suppose that is just a fancy way of saying "Ain't it purdy?", but I stand by the statement nonetheless.

In what I thought was a startling application, sunflowers also have a documented propensity for scrubbing heavy metals from the soil.  Lead, arsenic, uranium and radioactive species caesium-137 and strontium-90 will collect in the seeds of the sunflower plant.  Scrubbing would likely be particularly easy with the planting of perennial sunflowers.  One would simply need to cut the seeds from the stem to isolate heavy metals from the soil.  In fact,  sunflower planting initiatives have been put in place in both Chernobyl and Fukushima to scrub the radioactive isotopes from the soil in the wake of nuclear material release.

So there you have a few quick, interesting facts about sunflowers.  My understanding (and thus, this post), is not at all well developed, but I invite you to read more on the topic yourself.  Surprisingly interesting for what seems to be a generic flower.