Did you just sneeze? You did? Bless you. Late summer and fall allergies kick in when wind-pollinated plants shed their fine powder. While ragweed is well known as a main cause of seasonal allergies in North America, some identification issues persist. Especially this one: What is yellow and showy, often in bloom against a backdrop of early fall grasses and reddening foliage? That would be goldenrod. Because it blazes so brightly it still tends to be blamed for the seized-up sinuses caused by inconspicuous, allergy-inducing ragweed. Goldenrod is not to blame. Nor is ragweed is the only culprit.

Here’s a quick review of ragweed versus goldenrod, with a side of mugwort.

Photography by Marie Viljoen.

Goldenrod

Above: Goldenrod in bloom in September, with poison ivy’s foliage turning in the background.

Goldenrod is the common name for species of Solidago, which number over 100. Most are native to North America. They are valued for the beauty of their vivid flowers and for supporting the pollinators that visit them in droves when they begin to bloom in late summer and into autumn.

Above: Goldenrod lures pollinators.

Goldenrod does not cause allergies because its pollen grains are too bulky to be tossed around by a breeze and inhaled by us. Its vivid little flowers evolved to be seen and are designed to lure pollinators. Bees, wasps, hornets and hover flies, beetles and butterflies all find pollen-rich goldenrod flowers irresistible, and that is the point. The pollen is heavy and sticky and clings to the insects’ legs and bodies and is carried by them to the next flower, and, poof: Pollination happens.

(And this is true of all conspicuous—bright, beautiful, obvious—flowers. They are pollinated by creatures. Not by wind.)

Above: Goldenrod, not ragweed.

Above: Many goldenrods favor meadows and sunny spaces.

Above: Seaside goldenrods (like Solidago sempervirens) are exceptionally tough and able to withstand wind, salt, and occasional drought.

Ragweed

Above: The distinctly un-showy flowers of common ragweed (Ambrosia artimisiifolia).

Unlike goldenrod, ragweed (Ambrosia spp.) is a wind-pollinated plant. It produces clouds of fine pollen that irritates humans as the season shifts to autumn. But because goldenrod amplifies its presence at the time that ragweed blooms, its fireworks of yellow flowers often get the blame.

Above: A dense stand of giant ragweed (Ambrosia trifida)—note its three-lobed leaves

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