DALY: Though troublesome, pollen has a purpose

After a long, cold winter, springtime has finally arrived.

Redbuds, dogwoods, cherry trees, azaleas and many other flowering plants color the landscape. However, spring also brings on the pollen season.

For most people, it is just a nuisance. However, for some it can cause allergic reactions with symptoms such as itchy eyes, sneezing and other respiratory difficulties. In spite of the problems with it, pollen does play an important role in the reproductive processes of plants.

Pollen consists of tiny grains that are produced in the male parts of flowering and cone bearing plants. It is transferred to the female parts of the flowers resulting in fertilization and the production of seeds.

There are basically two kinds of pollen. Some plants, mostly ones with showy visible flowers, produce a large sticky substance that is spread to other plants by insects like honeybees. It is not dispersed through the air. This type of pollen seldom causes allergic reactions.

The other kind is wind blown pollen, which is the source of most of the problems. The light weight grains are produced by many trees and plants that usually do not have showy flowers. They shed their pollen into the air on warm, dry days, releasing large quantities of it to improve the likelihood of pollinating the female flowers.

Pine trees are an example of wind pollinated plants. They produce vast amounts of pollen which can cover everything. The individual grains have two large wings that help disperse it through the air. Often large clouds of it can be observed being blown on windy days.

The amount produced and released depends upon relative humidity, wind, and the overall health of the male pine cone. The yellow pollen from pine trees often gets blamed for the allergies. However, it is not a potent allergen and the individual grains are too large to penetrate deeply into the respiratory tract.

The real culprits are the various weeds, grasses, and trees such as oaks, birch, and hickory. Their pollen grains are much smaller and have chemicals that can cause allergic reactions.

Not much can be done to prevent pine pollen from falling on everything. Just wash it off and sweep it away, if possible. For the smaller grained pollen that causes allergies, there are a few tactics that can mitigate their effects. Limit outdoor activities during periods when the concentration is high. Weather reports give information on the pollen count so you can plan your day around it.

If you must work outdoors, wearing a dust mask can help in reducing inhalation of it. In the home, keep the windows and doors shut and use a hypoallergenic air conditioning filter. Rain can remove it from the air, as well as wash it away, and the levels are often much lower after a rainfall. If allergies are serious, consult with a physician.

As you can see, pollen is a necessary part of plant reproduction. The pollen grain is a container for DNA. This is the means by which genetic diversity is maintained by plants. Even though pollen causes difficulties for some people, we need to appreciate the important role it plays in nature.
