Don’t Blame Goldenrod for Your Allergies
Know the difference between goldenrod (Solidago species) and ragweed (Ambrosia species). There are over 75 different species of goldenrod and 20 species of ragweed native to the United States. Goldenrod gets the blame for your itchy eyes and runny nose, but the culprit is actually ragweed. Both plants are members of the Asteraceae family, grow in roadside ditches and open fields, and bloom at the same time. Goldenrod flowers contain nectar to attract pollinating insects, and the large, heavy pollen grains attach to the insect bodies. It is an important nectar source for pollinators. Ragweed flowers do not contain nectar, and the plants are dependent on the wind to transfer the small, lightweight pollen. This pollen has the ability to blow for miles. A single ragweed plant is capable of producing over a billion pollen grains. The next time you think it’s the beautiful goldenrod causing your allergy woes, think again. For more information, see HGIC 2326, Goldenrod & Ragweed.
Goldenrod has characteristic bright yellow flowers.
Barbara H. Smith, ©HGIC 2018, Clemson Extension
Ragweed has inconspicuous flowers that produce small, lightweight pollen that blows in the wind.
Barbara H. Smith, ©HGIC 2018, Clemson Extension
Goldenrod (top of photo) has bright yellow flowers at the tips of the stems. Ragweed (bottom of photo) has inconspicuous, greenish flowers.
Barbara H. Smith, ©2024 HGIC, Clemson Extension
Goldenrod has 3- to 6-inch simple, lanceolate leaves that are arranged alternately on the stem
Barbara H. Smith, ©2024 HGIC, Clemson Extension
Ragweed has pinnately loved leaves that are deeply lobed with 5 primary lobes. They are arranged opposite at the base of the stem but become alternate towards the top. The stems are hairy, and the foliage has a green, minty smell when crushed.
Barbara H. Smith, ©2024 HGIC, Clemson Extension
