Flower Science |
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Story and photos by Jim Murtagh An assortment of tweezers, razor blades, and other surgical implements were carefully positioned beside each dissection station. The six gray, dual-ocular, microscopes lining the sides of the table were reminiscent of a high school science class. At the center of the work table was a large vase filled with cut flower specimens. The aroma from the lilies permeated the room, and added a pleasant freshness to an otherwise sterile environment. The vibrant colors of the daisies, gladiolas, and astromeria contrasted with the pale color of the walls. If the flowers knew what lie ahead for them, surely they would have closed their buds and hid their showy petals. Following the teacher’s instructions, the class meticulously began the dissection process. The lily was the first to undergo the knife. The flower’s three outermost sepals were gently peeled away, followed by three interior petals. The central core of the flower was exposed, and its ovary was sliced longitudinally to reveal its precious egg clusters. The anther, which contains two pollen sacs, was carefully laid on the frosted glass of the microscope’s deck. The high intensity light from the microscope illuminated the specimen, and a slight twist of the focus knob brought the burnt sienna colored anther into sharp view. Under magnification, it was easy to see the translucent rice shaped pollen grains haphazardly sticking to the anther’s surface. Almost in unison, the class responded with a resounding “Wow!” just as promised by their instructor, Susannah Graedel, at the outset of the lecture. For the students attending the Adult Ecology Club program at Bauer Park in Madison , it was an exciting afternoon of hands on activity, mixed with scientific explanation. Graedel took the class on a fact filled journey through time, describing how life on Earth may have started, and how the presence of nutrient rich seed bearing plants allowed the earliest mammals to flourish. This class, “Flower structure through the microscope,” specifically explored how flowers have uniquely evolved to attract specific pollinators.
Graedel chose the lily as the first specimen to examine because its parts are large and it is easy to dissect. The second specimen, a member of the aster family, would challenge the newly acquired skills of the amateur botanists. Graedel took a bouquet of small white and yellow daisies from the vase and handed each student a specimen. She then shocked the class when she informed them that the plant they were holding was not a flower. The students were asked to remove one of the white objects resembling petals from the edge of the plant, and one of the fuzzy yellow center parts of the plant, and then study each under the microscope. With skepticism, the class followed the instructions, and within a few moments, a series of “wows” started to echo through the room again. It turns out the daisy is a composite flower, which means that it is actually hundreds of flowers arranged in a dense head to look like a single flower. Each white floret around a daisy is, in fact, a single flower referred to as a ray flower, and each yellow floret in the center of a daisy is called a disc flower. Under a microscope, each of these miniscule flowers had the same basic structure as the much larger lily. Graedel explained to the class that daisy they held was not a single flower, but rather hundreds of flowers!
Spring flowers will soon emerge from the ground, and the bleakness of the winter landscape will be replaced with an abundance of colorful of new growth. Nature is filled with more surprises, just like the daisy. If you are curious about the outdoors and the natural world, contact the Madison Beach & Recreation Dept. at www.madisonrec.com or 203-245-5623, for information about upcoming classes at Bauer Park.
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