July 21, 2016
Alien Dust
Copyright Bob Osborne
Recently one of my employees told me a story of driving to work when, from the side of the road, a cloud of yellow dust enveloped her car. Being a twenty-first century woman, she immediately thought about chemical warfare and other nasty scenarios. She was actually quite startled by this incident.
I informed her that most likely the ‘deadly’ dust was actually the very alive pollen of the pine trees she was driving past. This is the time of year when pines and other trees ripen their pollen and release it to the winds. In a large grove of pines the cloud of pollen produced by these releases can be quite astounding. A shake of a pine bough can produce puffs of sulfur yellow.
Recently I was given a book entitled Pollen, The Hidden Sexuality of Flowers by Rob Kesseler and Madeline Harley. This book is a revelation of the highest order. Seen as incredibly fine dust by our eyes, the individual grains of pollen are intricate and entrancing structures of nature that rival any flower we might treasure.
Using electron microscopy, botanists have been able to delve into the intricate details of these drifting male sexual organs. Their shape and surface features remind us of patterns we see, but there are forms that rival any science fiction movie for the bizarre and outlandish.
There are spheres, ovals and every shape you can imagine. Some resemble the round space ships of movies but have fascinating surfaces. The cover shot is of a pollen grain of an iris. It is a sphere of rusty brown but with pentagonal patches that themselves are composed of braids of cells.
Each pollen grain has what are called germinal apertures. These are usually depressed areas and are where the germinating pollen tube bursts through the outer wall and, if lucky enough to land on a receptive flower pistil, grows down to the waiting ovary. Very ancient flowering plants such as the magnolias generally have only one aperture, but more modern plants can sport many apertures.
Perhaps here a little botany will help. The flower has several parts. In complete flowers the stamens, which produce and release the pollen, usually surround a structure called a pistil. At the top of the pistil is the stigma. This produces a sticky substance that catches pollen grains and stimulates the pollen grain to grow.
The process of growth is incredibly rapid. A pollen tube leaves the pollen structure and moves downward through the narrow part of the pistil called a style and advances to the ovary, at the heart of which lies the embryo sac. Once the pollen tube reaches the embryo, it fertilizes it and the formation of seeds begins.
Looking at the bewildering array of pollen grains is like a trip to a different world. In a sense this is true. We cannot see or relate to the microscopic world. When we peer into this world with the help of new tools, we peer into a world that appears to be inhabited by aliens. And yet this is not an alien world, but the very same world we live in. In this world pollen grains have evolved spikes that help it catch onto the stigma. Other surfaces resemble corals or sponges. Some look like an exotic nut or seed. Many have a kind of natural lace covering. Some are weird enough to be hard to relate to.
Whether we peer into the heavens with our telescopes to see further and further into our apparently limitless universe or whether we peer into our microscopes to see further and further into a world that is around and within us, we see layer on layer. Each time we peel a layer there is another layer beyond. What is most startling is how complex these layers are.
For those interested, I would highly recommend finding a copy of this book. You will never look at flowers, or for that matter the natural world, the same way. Just as a photo of a distant galaxy can enchant and enlighten us, the photos in this book will realign your view of reality.