It's that time of year again: sneezing, runny nose, watery eyes. Many folks think their symptoms are caused by goldenrod, which are conspicuous along roadsides. Their yellow color fills fence rows, and sometimes spreads across fields. But this pretty wildflower isn't to blame; here's the culprit:
Ragweed is as inconspicuous as goldenrod is visible. You almost have to know what you're looking for to see their small, green flowers. The plants can easily be written off as just a bunch of weeds beside the road, although these Giant Ragweed plants grew to 8 or 10 feet tall in a cluster that ran 60 feet or more along the roadside.
Goldenrod and ragweed bloom at roughly the same time every year, and much of their ranges overlap. Goldenrod's bright color indicates they are pollinated primarily by insects. Ragweed's green flowers don't attract insects, and they release copious amounts of pollen into the wind. As a general rule-of-thumb, insect-pollinated flowers do not cause nasal allergies, while wind-pollinated species often do. So don't fear the pretty flowers.
There are about 15 species of ragweed in North America and more than 60 species of goldenrod.