It is not only the dip in temperature that signals autumn across our Niagara Frontier and the middle latitudes of North America. It is also our lovely fields of burnished gold.
Goldenrod is at once the most widespread, the most noticeable, and the most misunderstood of our fall wildflowers. A perennial, it rarely invades cultivated fields but few waste places, marsh margins, open areas in woodlots, or early succession fallow lands escape its attention. Its lovely fronds or racemes or umbels or plumes, depending on the species, attract honeybees and bumblebees, syrphid flies and treehoppers, as well as soldier and long-horned beetles with their sweet nectar and sticky pollen. These in turn attract predators: ambush bugs, wasps, crab spiders, and what is to me that scariest of all insects, the praying mantis. The mantis finds this wildflower so hospitable that it often forms its egg cases on goldenrod stems.
Meanwhile, the goldenrod defends against the depredations of moths, small flies, or midges by forming growths called galls. Most noticeable are spherical galls on stems, but there are also blister galls on leaves and bunch galls among the flowers themselves. The stem galls will remain evident in winter when the flowers and leaves have died back. Then birds like chickadees and downy woodpeckers will notice them and you will often find galls with pecked holes where the bird has sought out the gall resident to supplement its protein diet. Gray squirrels have a different use for these galls: they feed on the whole sphere like a nut.
Examine the individual florets of goldenrod and you will find two types. Those nearest the ends of the fronds are female. Only the flowers of the central disk include male stamens as well. An arriving bumblebee can deposit pollen on the ray flowers before clambering on to seek the nectar of those in the center. Unlike most plants the spike-shaped goldenrods bloom from top down, perhaps because in early fall they have more competition with late-summer flowers in tempting insects. Then they entice these pollinators with their tallest tassels. Later that won’t be so important: they will be among the few flowers remaining.
Goldenrods not only reproduce by insect pollination, but their roots also form rhizomes, bulb-like enlargements that are actually underground stems from which grow clones of the original plant. Left to their own devices, such plants form dense patches. An individual plant may then cover a ten-foot diameter circle. Occasionally in a field of goldenrod one of these plants will age and die, leaving that circular area to be replaced by other wildflowers. A lovely fall sight is one of these restricted areas with the purple of asters or teasels surrounded by a broad border of goldenrod yellow. Botanists have shown their humane side by terming these areas fairy rings.
One way that the goldenrod does not reproduce is by airborne pollination. Like other insect-pollinated wildflowers, its pollen is heavy. Very few microspores that cause hay fever—a remarkable misnomer for it is neither hay-related nor a fever—are from goldenrod. The real culprit is its common but little noticed neighbor, ragweed. For too long, goldenrod has shouldered the blame for this affliction. It did not, however, prevent Kentucky and Nebraska from choosing goldenrod as their state flower, but it may have thwarted it becoming our nation’s flower when this idea was widely supported a hundred years ago. It was nominated by author-gardener Katherine S. White but the rose won out.
In All About Weeds, Edwin Rollin Spencer begins his account: “He is blind indeed who does not know goldenrod, but he is a taxonomist if he knows all the goldenrods.” How true. About twenty goldenrod species are found in this region, with almost a hundred nationwide. Take into account hybridization and different-appearing forms of the same species and identification problems mount to punishing levels.
When goldenrod finally turns brown at autumn’s end, its seeds are ready for distribution. Like those of dandelions, each has a number of tiny filaments attached to one end. These act as wings to carry off this diminutive embryo in the very winds that will so soon bring winter. Individual plants produce thousands of these tiny seeds. Thoreau noted how “they cover our clothes like dust,” and added, “No wonder that they spread over all fields and far into the woods.”
Only one rare goldenrod species is palatable to humans, but goldenrod honey is a gourmet treat. The flowers were used by Native Americans and early colonists for yellow dye. And inventor Thomas Edison sought to create a rubber substitute with goldenrod sap. He even bred a goldenrod that produced twelve percent rubber. (Henry Ford gave Edison a Model T with goldenrod rubber tires.) This research was abandoned when synthetic rubber was produced during World War II.