Naturespeak A naturalist's view of the world

October 19, 2009

A Flight of Fancy Floss

Filed under: Uncategorized — wykes @ 8:16 pm

I wish Milkweed plants weren’t so dog-gone photogenic this time of year. I generally waste so much time admiring their artistic merits – you know those rustic pods spilling out cascading plumes of cotton – that I probably miss other more important elements of the autumn landscape. How many times did a Bigfoot cross the trail behind me as I was bending down to get “that perfect shot” of  a pair of milkweed parachutes intertwined on a branch?(Like this one).  What if that elusive S.E. Michigan Cougar wandered by as I was obsessively counting milkweed seeds and releasing them to the wind. How many front cover shots did I miss just because I was looking at an extremely common weed? Heck, what if that cougar  or some murderous Sasquatch  ever decided to sneak up on me as I was so engaged – what then, eh? Imagine the headlines – “Local Man Claims Bigfoot Attack – Has Only Blurred Milkweed Pictures to Prove It.”

O.K., you might see this all as a flight of fancy on my part, but consider yourself forewarned. Just because something hasn’t happened yet doesn’t mean that it won’t. But, as long as I’ve brought up the subject of milkweed seeds, I might as well continue with my observations and save you from undertaking  this potentially life-threatening activity. You can thank me later when you come up with that award-winning pic.

Milkweed pods erupt on sunny fall days in order to release their seeds to the wind. The plants produce four to six seed pods over the course of the growing season and raise them up from two to four feet off the ground in anticipation of this big flight. Laid up inside the pod like a pine cone (see below), the seeds are neatly- I might even say photogenically – arranged. I took the time to count the contents of one pod, before it was dis-articulated by the wind, and came up with a count of exactly 162 seeds. Actually, there may have been a few more, but I was momentarily distracted by something moving in the high grass behind me.  According to the literature, the average milkweed pod will have anywhere from 100-200 seeds, so my interrupted count was well within expectations.

In the case of the above pictured pod, I had to pull it open to reveal its internal structure. It didn’t take a Bigfoot-like effort to do this because there is a naturally weak seam on the lower outward facing edge. Normally the casing dries out and splits along this seam of its own accord. Commercial milkweed growers (yes, there were such folks) collected the green pods  in late August and waited until they were down to a 10% moisture content. Their pods were opened with gentle agitation. There is a center “wall”, running the full length of the pod, and the floss end of each seed is loosely anchored to this septum. With the central seed core exposed, passing breezes are allowed to lift up the edges of the flat seeds and each unit, seed and attached floss, launches into the air.  Once one goes, the rest will peel off in rapid succession and leave the central septum bare (see below). These flossy parachutes lift their heavy seed load aloft and carry it as far as the wind will allow.

Scientists talk about the spread of air born seeds in terms of what they call a “seed shadow.” This represents a 4 dimensional area determined by the length, width, height, and even “hang time” of the seeds as they leave the maternal plant. Given that milkweeds have large seeds, this shadow is short but dense. Speaking of scientists, I feel compelled to tell you a few more useless Milkweed facts as determined by researchers. I mentioned commercial growers earlier, because there have been several pushes over the years to make use of milkweed floss. During World War II it was collected as a Kapok substitute and more recently it has been investigated as an insulator & textile material. Apparently this floss is equivalent to the density of goose down and possibly better in terms of insulating qualities. It takes 500 pods to accumulate 1 pound of this magic floss. If I’m figuring right, that means that one would need to harvest 75,000 seeds in order to get one measly pound of floss.  I know it would take far fewer geese in order to get the equivalent amount of down, but I wonder if a pound of goose feathers is heavier than a pound of floss?

Finally, I would be remiss not to mention that milkweed floss is extremely water resistant when endowed with its natural coating of wax. When that wax is removed, however, it can absorb 75% of its weight. This led some researchers to explore it as a potential diaper material. Unfortunately, I think this is certainly an impracticable path to follow. Everyone knows that Bigfoot fur is far more absorbent (consider this a hot tip for you potential entrepreneurs out there).

1 Comment »

  1. I found myself actually laughing out loud while reading your post! You have quite a way with words! Delightful!

    I, too, am obsessed with milkweeds. First, its’ the flowers, which I seem to photograph all season long. Then it’s the pods and those wonderful, wonderful parachutes inside. Photographically, and tactilely (?), I cannot resist a milkweed pod whose side has ruptured and whose innards are spilling out! You are not alone!

    HM…now I wonder how many Bigfoots (Bigfeet?) have snuck by me as I’ve been absorbed by the wiles of a milkweed plant…

    Comment by Ellen — October 21, 2009 @ 1:18 pm

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