It's Pollen Season

Soon our outdoor landscapes will come alive with a multitude of fresh colors as flowers bloom, leaves unfurl, and a host of young plants sprout from the ground. This onslaught of growth and life also spurs on the unpleasantness of allergies in some as large amounts of pollen are expelled into the air.

Pollen is produced by the male part of the flower known as the anther. This pollen is expelled in the hope that it will reach the female ovule; and, a young seed will be produced later in the season. Some trees contain both male and female parts; these trees are called monoecious plants. Some trees have separate genders and are called dioecious plants.

Colorized pollen from electron microscope

In most monoecious plants the male flower lies below the female flower. At first thought this may seem counterproductive since this arrangement would not be ideal for the pollen reaching the ovule on the same plant. However, this setup would prevent self fertilization which promotes more diversity which is more beneficial to the species as a whole.

Plants having small inconspicuous flowers like the maple, elm, or ash rely on wind pollination. Plants with large showy, fragrant flowers like dogwood, crabapple, and magnolia are pollinated by insects or birds.

Trees are the first plants to produce pollen; and, this production can run from January to June in Maryland depending on the weather. At its peak pollen production can be astronomical, causing sniffles and red eyes for those with allergies, along with sticky buildup on cars, outdoor furniture or anything else that is left outside beside a tree.

Dry windy days have the most pollen while heavy rains can wash much of the pollen out of the air. The trees that cause most allergies include ash, boxelder, sycamore, hickory, and pine. Despite these drawbacks, pollen is an essential part of plant reproduction and life on our planet.

Article by Mike Kay, Fredrick County Forestry Board

Nature Notes for 4/9/22