It was a gorgeous day that followed a series of not-so-gorgeous days. The sky was a deep crystalline blue, the sun was bright and hot and the temperature was in the 50s. I had been cooped up inside all day and I needed to get out and stretch my legs, so I grabbed my camera and headed down into the meadow.
As I walked along my trails, I took in the beauty of the season. All of the flowers I had passed during the summer were long gone, but they had been replaced with equally beautiful reminders of their former presence — seeds. The New England asters that had bloomed with their magnificent purple flowers now presented delicate and lovely balls of silver-gold seeds that looked like little urchins that had been stolen from the sea and placed on display for all to enjoy.
Then there were the smaller, more unobtrusive seeds that required a little focus and attention to observe. Basically, the meadow was a massive storehouse of food for birds. The abundance of seeds was in anticipation of the interest of hungry mouths in the winter. If just a few of the seeds could escape consumption, then the futures of all the plants would be secure. The only question that remained was how the plants would disperse their seeds.
We are all familiar with the wind-based dispersal of dandelions and many plants use this particular method. Some plants even time their seed dispersal to coincide with the presence of snow on the ground. This allows the seeds to be carried greater distances as they are blown across the top of a snowy field, like little tumbleweed plants.
All of this was rattling around in the back of my mind while I was walking along and looking for bird nests. It’s always interesting to have these secrets revealed when the trees drop their leaves and I wasn’t disappointed when I found a small nest not far from the Thinking Chair where I had spent so many hours this summer. So obvious after the leaves were gone, the nest had gone completely undetected by me.
I walked off the trail into the tall grass to get a little closer to the nest with my camera, took a few shots and then returned to the trail. When I looked down at the ground to check my footing, I was stunned to find my legs covered with seeds that had grabbed onto the fabric of my pants. There must have been a couple hundred of them and, with a sigh of exasperation, I set about the process of picking them off of me a few at a time.
What had I stumbled into? After removing all of the hitchhikers, I retraced my steps and carefully scanned for the source of the seeds. When I reached the point where I had stopped to photograph the nest, I found what I was looking for. It was a small ball of dark brown seeds that sat atop a very slender stem. I could even see that half of the seeds were missing.
So, carefully, I picked a second seed head that I hadn’t stumbled into and went back to the trail. Once again I discovered that new hitchhikers had managed to snag the fabric of my pants even though I thought I had been so careful. A dead plant had outsmarted me and I wasn’t feeling particularly intelligent at that moment, but at least I had solved the mystery.
The seeds were those of a bur plant and they had performed exactly as they had evolved to. Each of the seeds was basically the shape of a small canoe paddle. The actual blade of the paddle contained the seed itself, while the handle of the paddle was long and slender with a curved hook at the end. A close look at the hook shows a shape that a fisherman would find very familiar.
The hooks are perfect for snagging the fur of passing mammals, or in my case the fabric of my clothing. Once embedded in fur or fabric the seeds will detach from the parent plant and ride for as long as they can. Grooming behaviors may result in the removal and “disposal” of the seeds, or time may work its magic and the seeds will be shed along with the hairs they are attached to. Either way, the plant managed to disperse its offspring some distance from the spot where it grew.
I’d say to keep an eye out for burs and the many other plants that produce seeds that are dispersed with this hitchhiking strategy, but it would be virtually useless. The seeds are everywhere and they are nearly impossible to find until they are stuck to your clothes. Don’t let that discourage you from taking a walk, however. The rewards are so much greater than the slight annoyance of being bested by a plant.
Bill Danielson has been a professional writer and nature photographer for 23 years and he is outwitted by plants more often that he would like to admit. He has worked for the National Park Service, the US Forest Service and the Massachusetts State Parks and currently teaches high school biology and physics. Visit www.speakingofnature.com for more information, or head over to Speaking of Nature on Facebook.