Wind power propels plant propagation

A few weeks ago I sauntered along a marsh edge with my camera ready, hoping to photograph one of the many migrant birds, or perhaps a weasel or fox hunting.

My patience and timing, however, were not rewarded. Winged and four- legged creatures were scarce. Was it the overcast day, the cool temperatures, or the autumn winds?

Whatever the reason, the only things moving were the tree branches, falling leaves, a few bulrushes, and a lone plant bearing the last vestiges of summer.

A single thin stalk supported several shriveled flower heads and three fluffy cotton balls. Entangled with them was a stem of grass resembling a stalk of wheat.

Since there was still no sign of bird or beast, I decided to take a closer look at the flowers and seed heads.

As I knelt down and focused the camera, a couple of problems presented themselves. The clouds reduced the amount of light and the breeze kept the flower swaying.

This called for a tripod so I could minimize any camera movement.

After determining where to aim the lens, extending the tripod legs, and focusing, I was finally ready to snap the photo. As I looked through the view finder, however, I noticed something I had not seen from a standing position.

Every few seconds, the flower stem leaned with the wind, then rebounded to its original position once the wind calmed. Each time, however, the seed heads were a different shape. In fact, they were coming apart.

The wind was dislodging a seed or two on each and every time the flower bounced back to an upright position. Wind, water, and animals all aid in seed dispersal, but the wind is probably responsible for transporting the largest numbers.

Some seeds, like those I was attempting to photograph, are very small with a light, parachute attachment. The slightest breeze was enough to dislodge them from the plant and then lift them up and away.

Larger seeds from nearby trees such as spruce and maple are too heavy for the parachute method of travel. Instead those seeds had an attached wing. As soon as their seeds begin to free-fall from the treetop, the wing creates a spinning motion resembling a helicopter.

So, instead of dropping straight down, they ‘fly’ away from their parent tree, often landing many metres away. A mature tree will easily release thousands of seeds with a chance a few of them will land on fertile ground.

Most of this business about seeds was not on my mind when I first noticed the faded flowers and seed heads.

I did realize, however, the seed heads would soon disappear if I waited for either the sun to break through the clouds or the air to be still.

So, with the tripod fixed, the shutter speed as high as possible, I snapped the photo.

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