Goldenrod vs Ragweed – who is the guilty party?

Pretty soon the dreadful “hay fever” season will be upon us. Late summer and early fall brings different wildflowers in the fields and roadsides, and one of the most noticeable wildflowers is the pretty yellow Goldenrod.

Tennessee has several different species of Goldenrods, some are tall, others short; some have the flowers in plumes, others in spikes. Many people blame Goldenrod for their itchy eyes, runny nose and sneezing; however, the true culprit for these symptoms is a non-descript wildflower that doesn’t attract attention to itself: the dreaded Ragweed.

The bright yellow Goldenrod flowers attract bees, butterflies and other pollinators. Their pollen grains are sticky so they will attach to the legs and bodies of the insects that visit the flowers to drink the nectar. When the insects go to another plant, they transfer the pollen to other flowers, completing the pollination process so seeds can form.

Ragweed, on the other hand, does not have brightly colored flowers because it is wind pollinated. It does not have to attract pollinators. Ragweed is a “monoecious” (pronounced: mon-EE-shush) plant. It has the pollen-producing male flowers at the top of the stems, separate from the female flowers lower on the stems that produce the seeds.

The female flowers consist of two small, thin, thread-like pistils. The spikes containing the male flowers can produce up to a billion tiny, light-weight pollen grains.

Because the targets of the pollen grains are the little pistils on a different plant, Ragweed uses what I call shotgun pollination, by releasing billions of pollen grains. At least a few of them will hit their target. Unfortunately, some of those grains end up in our eyes and nose when we are outside, inducing allergic reactions.

There are three different species of Ragweed in our area, Common, Lanceleaf and Giant Ragweed which can grow up to 16 feet tall! You may wonder what redeeming qualities Ragweed could have if it causes so much misery. When the female flowers are pollinated, they produce oil-rich seeds that are an important food source for birds.

So, stock up on tissues, allergy medications and anti-histamines to be prepared for Ragweed season! Achoo!!!

Kris Light photographs wildflowers, animals and anything of interest with many of her best photos used in her website: click Search All Galleries to see photos. Her Outreach Science classes are available for public, private and homeschool groups through the AMSE. Kris welcomes questions at email.