Goldenrods -- © 2008 Dave Spier
First, to clear the air, goldenrod does not cause hay fever or allergies. That job is done by ragweed, a distant relative with tiny, inconspicuous green flowers and copious amounts of powdery, wind-blown pollen. Goldenrod, on the other hand, has sticky, relatively-heavy pollen carried from flower to flower by insects such as wasps and bumblebees. In fact, the yellow color of golenrod serves to attract the various insects needed for pollination.
Wherever there's abundant sunshine, goldenrods take over with a tangle of underground roots and chemicals that inhibit the growth of competitors. It takes a number of years, but they can dominate small patches of real estate and this continues until shrubs rise above the challenge and begin shading the goldenrods. Assuming there are no other disturbances, trees eventually win the battle for sunlight and recreate a forest, but that takes decades. That said, there are even two species of goldenrod, the Zig-zag and the Blue-stemmed, that survive as individuals or small patches in some woods.
There are actually dozens of different goldenrod species, each adapted to slightly different growing conditions. Many have offset, but overlapping, growing periods so they are not all competing for insect attention at the same time. The individual blossoms are crowded together, usually along the top stems where they are most visible. To see the differences in their basic structure, one needs to look closely or use a magnifying lens. Many resemble miniature daisies. Of course, many things do because the daisy family (usually called the aster family) contains one-tenth of the world's flowering plants. Their basic design is a central disk of compact florets surrounded by showy petals called rays. There are a few exceptions to this rule, including ragweed, which has lost (or never developed) the corolla of rays. Unfortunately, ragweed blooms at the same time, and in many of the same habitats, as its showy cousins that get the blame. So, if you can, spare the gold and pull the ragweed.
You might call me the goldenrod ambassador.
Contact me at firstname.lastname@example.org
(This copyrighted article and photo first appeared in the Times of Wayne County, August 25, 2008. All rights reserved.)