Frank Bures: Ragweed or goldenrod?

September 9, 2018
Dr. Frank Bures

The thoughts in this Hint have appeared in years past at this beautiful time of year, when we enjoy the last vibrant colors of nature, before we have to endure our monochromatic, frigid hibernation season.

In the fall many beautiful wild flowers blossom brilliantly in the meadows and along roadsides. Also in the fall many people’s beaks blossom blatantly from the constant blowing and wiping caused by nasal allergy to ragweed pollen. Yet, most of these folks do not realize that the tall bright yellow flower at which they glower is not ragweed, but goldenrod. Goldenrod, though somewhat related to ragweed, is in no way responsible for the sufferer’s drippy despair.

Both plants are members of the family Asteraceae (aka Compositae). That’s where the similarities end. Goldenrods (there are about 100 varieties) have a slender stem with bright yellow to deep gold, long flowers that grow in thick, graceful clusters on the stem’s end. Ragweed, in contrast, has drab, greenish long flowerheads that are more erect. The height of the plants can be similar, probably giving rise to some confusion on viewing them. Goldenrod is the state flower of both Kentucky and Nebraska. Nobody has claimed ragweed yet.

The pollens are also very different. Pollen from goldenrod has never been implicated at all in any allergy. The bright color of goldenrod is meant to attract insects as pollinators. For that reason, we humans surmise, it is heavy and sticky and not easy to blow about. Not so with ragweed pollen, which is designed to be distributed by the wind. This is a chancy affair, and so the plant must produce huge amounts of it, as many people well know. The threshold for allergic reaction is only 25 pollen grains per cubic yard. During blooming season the pollen can be a lot more prolific than that.

Goldenrod has a number of helpful qualities. As an herbal medicine it has been used for wound healing and various other ailments. Known to cause tissue water loss, it is taken as a tea in Europe to treat inflammation of the urinary tract and kidney stones. Thomas Edison discovered that goldenrod contained latex and began to develop strains that could be a commercial source of rubber. However about the same time German chemists developed a petroleum based synthetic rubber, which government subsidies made more attractive. Is there elastic gold in them there rods, not to be sneezed at?

So spare the goldenrod and rag on ragweed. This is a small attempt to clear up goldenrod’s tarnished reputation, so that you can properly enjoy its offering of seasonal beauty. Sort of a ragweed to goldenrod story.

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