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Speaking of Nature: Much ado about pinecones

  • On a mature white pine, clusters of 20 to 30 male cones will be found at the tips of nearly every branch. The pollen, like powdered sugar, will be carried up to the waiting female cones by a good breeze on a nice day. For The Recorder/Bill Danielson



For the Recorder
Monday, June 11, 2018

I’ve noticed a definite difference in the weather this spring. In general, the temperatures have been cooler, the skies have been cloudier and the weekends appear to be somewhat rainier. I could pour through the weather records for past years to collect data that would back up this feeling, but it is far easier to simply look out the window and judge the condition of my lawn.

The ground itself isn’t particularly wet, but the clear days that are good for mowing have generally been weekdays when I am busy at work. By the time the weekends roll around, I am either busy with social engagements or stuck inside due to poor weather. All the while these cool, wet conditions provide ideal growing for the grass and it gets deeper and deeper with every passing day. So, it was with focused intent and great resolve that I went out to confront the situation on a recent sunny Sunday morning.

Anyone who maintains a lawn, especially a larger lawn that requires a larger machine to get the job done, will be familiar with the notion of following the “ideal pattern.” This pattern may need to be adjusted if the grass gets especially deep, but for most of the mowing season there is absolutely a “best” way to attack the problem. It’s just the way things go.

So, after making a slight adjustment in my attack, I settled into a familiar pattern. First I make a series of “left hand” passes (counterclockwise direction) and then I reverse the direction and complete the same circuit in a series of ever diminishing “right-hand” passes. This pattern of establishing a “grain” and then immediately going against it seems to be the best way to deal with longer grass at my house. As the summer matures I only need to make a single series of left-hand passes.

It was during this carefully calculated assault that my beautiful wife, Susan, suddenly appeared. A bright smile on her face, she was exalting in the fresh air and the rare moment of sunshine. Needless to say, the mower blades were immediately shut off and I drove over to greet her joyful presence. We exchanged the predictable pleasantries about the beauty of the day and then her attention was caught by something in the branches of the white pine tree that we were standing next to. “What are those?” she asked.

What she had noticed was a lovely clump of pollen cones growing on the low branches of the tree. She had absolutely no idea what they were, but apparently she thought the butter-yellow color of the cones was particularly beautiful when set in contrast to the dark green needles of the tree. I, of course, agreed with her and I launched into a impromptu presentation on pine reproduction.

It turns out that the idea of a pinecone is well understood by most people. Pine trees have pinecones. But what, pray tell, are they for? Well, believe it or not, pinecones got their start as a precursor to flowers. Pine trees belong to a group of trees called gymnosperms, which first evolved in the Carboniferous period some 300 to 360 million years ago. At this point, plants did not have flowers that relied on pollinating insects, but instead relied on wind and water to assist them in their reproduction. Gymnosperms favored structures that we call “cones.”

In the spring, pine trees produce two kinds of cones: male and female. The female cones, which eventually turn into “pinecones,” are generally found in the upper branches of larger white pines, whereas the male cones are located lower on the tree. It is important to note here that other gymnosperms like hemlocks, spruces and firs also have cones. “Pinecones” are only found on pine trees.

In an effort to reduce self-pollination, the male cones are low on the tree so that gravity alone does not deliver pollen to the female cones. Instead, a good breeze is required to carry pollen from one tree to the next. This is also helped by dry weather, which allows the pollen grains to float in the air with maximum effect.

Well, as many of you know, this particular strategy is effective, but somewhat messy. When conditions are just right, a stand of white pines can release enough pollen to coat the landscape. Cars, decks, parking lot puddles and even swimming pools can turn yellow in the course of an hour or two. Even worse is the effect on human sinuses. When the pine trees get rolling, our allergies can go crazy.

As our wonderful encounter came to an end, Susan bid me adieu and I resumed my mowing. As I drove past the pine trees in my front yard, I took stock of the sheer number of the male cones on their branches and breathed with a slight sigh of relief. The cones were almost ready to burst, but I had beaten them by a day or two. Had I put off mowing any longer, I would have been showered with clouds of yellow pollen every time I passed a tree and bumped a branch.

If you have a white pine growing in your yard, I would highly recommend that you go out and visit it on the next “perfect” day that we have. Take a look at those male cones and, if you are brave, tap the branch with your finger. If conditions are good you should see a noticeable puff of pollen released into the air. If you are like me, however, you won’t stick around for long. The sneezing should start soon after!

Bill Danielson has been a professional writer and nature photographer for 20 years. He has worked for the National Park Service, the U.S. Forest Service and Massachusetts State Parks, and currently teaches high school biology and physics. Visit www.speakingofnature.com for more information, or go to Speaking of Nature on Facebook.