All that is gold, does not glitter. Especially in September… when the goldenrods bloom.
Ahhhhh chooo! I don’t like that plant. Goldenrods make me sneeze! So you might say.
Not so fast. Goldenrods get a bad rap for fall allergies, although they are unlikely to be the culprit for your itchy, watery eyes. Goldenrod pollen is insect pollinated and has a difficult time finding its way to your sinuses.
Ragweed is the likely suspect, as it blooms about the same time as goldenrod and is wind pollinated, making it more likely to be inhaled. Blame it if your eyes water and your sinuses are congested.
Now that you’re not nervous about getting acquainted with goldenrods, take a closer look. Do you see interesting-looking formations on some of the plants? Those are goldenrod galls. An gall is simply an abnormal growth, and in this case, caused by an immature insect.
The two most common goldenrod galls you’re likely to see on the Illinois’ prairie are the ball gall…
…and the bunch gall.
The ball gall is made by the tiny goldenrod gall fly. She lays her eggs on a goldenrod stem, and about a week or so later, the larvae hatches. It chews a tunnel into the stem where it sets up housekeeping for up to a year. The goldenrod stem gradually swells around the larvae, providing a safe spot for it to live and feed. Think of it as a spherical bed and breakfast.
If you enjoy fishing, as I do, you’ll know a ball gall is a good place to find bait. Cut open the ball gall, scrape out the larvae, and you’re in business. Woodpeckers and hungry, insect-loving birds are also in the know. You’ll sometimes find them pecking at ball galls, looking for dinner.
Bunch galls are formed by the goldenrod gall midge, a tiny fly which lays its eggs in the leaf buds. The larvae short-circuits the normal growth of the plant, resulting in a an explosion of leaves that sometimes look like a stacked rosette, as you see in the photo above.
If you’re lucky, you might find a ball gall and a bunch gall on the same goldenrod plant.
And — no worries. Although they do take nutrients from the goldenrod, most goldenrod galls are believed to be harmless. The plant is irritated, but tolerates them. Sort of like you might put up with the out of town relatives that were supposed to come to your house for the weekend, and stayed for a month.
Looking for different goldenrod galls on the tallgrass prairie is a great excuse to go for a hike on a sunny day in September.
But really…who needs an excuse?
All photos by Cindy Crosby. (Top to bottom): Goldenrod (Solidago spp.) and big bluestem (Andropogon gerardii), Russell R. Kirt Prairie, College of DuPage, Glen Ellyn, IL; goldenrod, Schulenberg Prairie at The Morton Arboretum, Lisle, IL; ball gall, RKP; bunch gall, RKP; ball gall, RKP; bunch galls, RKP; ball gall and bunch galls, RKP; autumn at Nachusa Grasslands, Franklin Grove, IL.
Some of the information in this essay is taken from the following sources: Brandeis University: http://www.bio.brandeis.edu/fieldbio/galls/galls.html; http://www.fcps.edu/islandcreekes/ecology/goldenrod_gall_fly.i.cfm.; http://www.hiltonpond.org; www4.um.edu/fieldstation/naturalhistory/bugoftheweek/galls_i.cfm; http://prairieecologist.com/2013/08/27/goldenrod-allergies-and-spitballs/; Web MD: http://www.webmd.com/allergies/features/ragweed-pollen
The quote that begins the essay is from J.R.R. Tolkien’s The Lord of the Rings.