We’ve all heard that old adage, “April showers bring May flowers.” Not only is it short and sweet, but it also rhymes, like a decent adage should. Furthermore, it evokes powerful images of bright and colorful flowers like tulips and lilies. This is certainly a reasonable image to find one’s self contemplating, but it turns out to be a somewhat narrow and chauvinistic one.
It turns out that there are two main methods that plants rely on for transferring pollen from anthers to pistils. First, we have the familiar model of the plant and the insect pollinator. Plants that rely on insects (and sometimes birds, and sometimes even mammals in special circumstances) have to include a bribe of some sort to get the help that they require. This bribe is almost exclusively some kind of food.
Ask my wife and she will tell you that this ploy works on humans as well as it works on insects. On a quiet Saturday morning, when all I want to do is sit and read, I can often be motivated to certain chores that I simply have no interest in doing if food is offered as a bribe. This is most obvious in the winter months when I often hear the following proposal: “I’ll cook breakfast if you’ll shovel the driveway.”
The same approach works with flies, bees, moths, butterflies and all sorts of other insects. Offer some good food and you can get stuff done. So, like any good restaurant that has good food to offer, you need a sign to advertise. Thus, the big, fleshy, luxurious, aromatic flowers of certain plants are designed specifically to attract pollinators. Sometimes the relationship between a certain plant and a very specific pollinator is so important that the flower will only offer food to that one creature alone. Orchids are well known for this sort of hyper mutualism.
Well, that certainly is one approach to the problem of pollen distribution. However, there are other plants that rely on the wind to assist them in procreation. Flowers that do not need to attract pollinators are free to be small, somewhat colorless, and almost invisible as a result. These are the kinds of flowers that one can find in abundance in the forests of the Northeast and they add a certain beauty to the landscape of early spring.
These past weeks, as I have made my regular commute to work, I have enjoyed watching the subtle, but beautiful emergence of these small, unobtrusive flowers. Especially in trees like birches and cottonwoods, the production of thousands of little flowers transform a “dead” tree into an object that more closely resembles a hollow sphere that has been frosted with paint. Some of the trees turn a muted shade of red, while others turn a pale yellow-green.
There is one drawback for the plants that rely on wind to spread their pollen from place to place. Because there are no pollinators to guide the pollen to specific targets, the amount of pollen used has to be amped up a lot. Lots of pollen has to be released for a fairly long time to ensure that just a little bit of it hits the mark. This does require some investment of energy on the part of the plant, but it has a particularly negative impact on certain members of the world’s human population.
All of that pollen floating around in the air creates a particulate fog of plant reproduction that is usually invisible to the naked eye, but is unpleasantly apparent to the human nose. Seasonal allergies in the spring are basically a negative reaction to the reproductive efforts of trees and other wind-pollinated plants. Our noses start to run and our eyes start to water when the plants inadvertently try to pollinate us. Even as I type these words I am suffering both of these symptoms and thinking, “Come on, guys — get a room!”
Last week I looked at some female flowers from a red maple near my driveway and this week I’m sharing a photo of the flowers of a cottonwood tree. In wind-pollinated species, the male flowers are often larger and more interesting because they have to produce so much pollen. In cottonwoods, the flowers are arranged in structures known as catkins. This term is Dutch in origin, from the word “katje,” which means “kitten.” At one point, someone thought this particular flower arrangement resembled a kitten’s tail.
Things happen very quickly at this time of year, but for the moment, a lot of what you see on the trees is not leaf, but flower. I’ll try to get more images of different flowers and in the meantime, try to get outside and enjoy the beauty of the season. Just don’t forget your allergy pills!
Bill Danielson has worked for the National Park Service, the U.S. Forest Service and the Mass. State Parks. He has been a professional writer and nature photographer for 19 years and also teaches high school biology and physics. Visit www.speakingofnature.com for more information or go to Speaking of Nature on Facebook.