It’s that time of the year again: allergy season. And for those that are sensitive, it can mean months of suffering from continuous runny noses, itchy and puffy eyes, and sneezing that doesn’t let up. Though long blamed, one common plant has been wrongfully accused of being the culprit for these uncomfortable symptoms, but the truth is goldenrod is not the enemy, it doesn’t pollinate the right way.
Goldenrod is a perennial that favors open areas such as meadows and prairies and is well known to be a primary succession species that will move into and recolonize disturbed areas. Another primary succession champion that is often the culprit of hay fever is ragweed which reportedly causes 50% of cases of seasonal rhinitis – and blooms at around the same time as goldenrod.
One could guess how goldenrod has been easily misidentified as the cause of so much suffering, with bright yellow flowers that branch off the top of the main stem and sway in the summer breeze. Goldenrod produces between 5 to 60 disc florets which house numerous tiny, yellow flowers along its length. Ragweed on the other hand is a fairly inconspicuous weed with multiple spikes housing many tiny, green flowers over intricately toothed leaves. The major difference between the two is that ragweed wind pollinates and goldenrod doesn’t, instead goldenrod relies on pollinators such as bees and butterflies. This difference in life history means a world of difference for those that suffer from seasonal allergies.
Wind pollination is a system widely used in the evolution of plants and can produce very good results. The wind blows most days, so why not rely on something reliable that will never disappear? Plants that take advantage of this system do not invest their resources in producing eye-catching flowers, alluring scents, nor sweet nectar because they are not trying to attract pollinators to their flowers. Instead, they display small flowers which produce large amounts of light-weight pollen that is easily carried by the wind. Some other plants that employ wind pollination are corn, wheat, rice, and pine and spruce trees. The spores of funguses are also carried by the wind.
Ragweed doesn’t have the intention of causing allergies when it releases its pollen to the wind, it is merely doing its thing – and very well. And goldenrod, well, it has become the scapegoat for the nuisance caused by ragweed’s pollen but never the less it just keeps blooming on.
Story and photo by Gabrielle L. Wheeler
