The Misunderstood Goldenrods

Charlotte and I just returned from a short vacation along the sandy shore of northern Lake Michigan, south of Gulliver in the Upper Peninsula of Michigan. Much to our surprise and joy, several federally endangered and threatened wildflowers appeared to be quite at home on that broad, sandy shoreline. One, the very rare Pitcher’s or Dune Thistle, is also found along the dunes at Whitefish Dunes State Park in Door County.

The Giant Goldenrod, one of our state’s largest, can grow to 7 feet in height.

Another wildflower, both state and federally threatened, was the Houghton’s Goldenrod, Solidago houghtonii. That this very attractive little plant would receive such a high rating surely would surprise especially those people who firmly believe that goldenrods cause hay fever – wrong! Their relatively waxy and heavy pollen cannot be carried by the wind but, instead, must be transferred from one goldenrod to another by insects.

The real culprit that brings about sneezing during this season is the difficult-to-see, green-colored Common Ragweed, Ambrosia artemisiifolia, whose dust-like, wind-carried pollen is the bane of hay fever sufferers. Even though you may not have Common Ragweed growing near your place, the pollen can be carried for miles by the wind.

I truly hope some of you unfortunate hay fever-afflicted readers don’t test me out! A patch of goldenrods will, in fact, act as “feather dusters,” cleaning the air of all sorts of grains of dust and pollen. Mark my words, you’ll return from your walk through a large patch of Canada Goldenrods, for example, wishing you hadn’t done so. Also bear in mind that the pollen grains of the goldenrods will not cause you to sneeze.

It always gives me great joy to learn that a certain plant has been named to honor a great and deserving botanist. Such was the case with Houghton’s Goldenrod, named in honor of Douglass Houghton, a doctor, botanist, civic leader and Michigan’s first state geologist. He discovered this rather dainty little goldenrod in Mackinac County in 1839, between what are now the communities of Naubinway and Epoufette along the north shore of Lake Michigan.

This endangered plant especially favors growing along moist sandy beaches and particularly in the interdunal wetlands, which is exactly where we observed them where we stayed. There they not only receive plentiful moisture but also more protection from strong southerly winds coming off Lake Michigan. Other plants which commonly grow in with these goldenrods, and which we also observed, are the Grass of Parnassus, Kalm’s Lobelia and the Shrubby Cinquefoil.

The wide-toothed leaves of the Zigzag Goldenrod stand out in the forest.

Wisconsin lays claim to about 20 species and varieties of goldenrods, a rather large percentage of the approximately 100 species occurring in the United States. Interestingly, there is only one British species, Solidago virgaurea, the European Goldenrod. However, sensing the late summer and fall beauty of several North American species, the British have imported some showy species to be used as tall golden backdrops in their excellent gardens.

The genus of goldenrods, Solidago, (sol-i-DAY-go), is from the Latin, “solidare,” meaning to join or make whole. In the olden times it was common to cut goldenrod plants into small pieces, boil them in water and use the liquid as a healing wash for wounds.

We too favor one of the tall species, S. gigantea, the Giant or Late Goldenrod. This species resembles in several ways the abundant, weedy, aggressive and quite variable Canada Goldenrod, which can grow virtually anywhere, including moist to dry habitats, along roadsides or in fields, woods or prairies. The Giant Goldenrod likes to grow in relatively wet environments. The tallest of the several growing next to our east stone retaining wall is just about six feet tall, undoubtedly in response to my frequent watering.

The frosted stem and tipped-over flower head mark the Gray Goldenrod.

Many species of goldenrods are very fascinating, beautiful and often quite solitary, unlike the enormous groups of Canada Goldenrods. We have more Canadas than we wish throughout our five-acre field and along the edge of our garden, succeeding very well in invading the loosely tilled soil. Try to pull or dig them out and you’re in for a surprise; what tenacious root systems those hardy perennials have.

Spend some time in the middle of a goldenrod patch observing the numbers of visiting insects on the blossoms. Butterflies especially will be on hand, along with moths, flies, bees, wasps, hornets, beetles and maybe even a few “bugs,” including the interesting Ambush Bugs. What an ideal place for a youngster to start an insect collection.

One of my favorites of all goldenrods holds its own very nicely into October – the Gray Goldenrod, also known as Dyer’s Weed, S. nemoralis, (nem-o-RAY-lis). Due to the poor soil in the stony ditches where many grow, they are frequently no taller than eight to 10 inches, dainty little plants with very fine hairs giving them a grayish bloom or cast. The plant is so easy to recognize because of the tendency of the flower top to bend over.

This delicate Houghton’s Goldenrod is both state and federally threatened in the Upper Peninsula of Michigan.

The fact that the closely related goldenrods tend to hybridize makes accurate identification difficult at times. Years ago I obtained the help of a professional botanist who worked out excellent keys to the asters and the goldenrods. Now each student in my field classes was able to make honest attempts to key out the goldenrods. Getting to know how to use scientific keys to identify wild plants will prove to be extremely useful. A favorite field guide of ours, Newcomb’s Wildflower Guide, has a very good keyed section dealing with the goldenrods.

The shapes and margins of the leaves usually help to identify the goldenrods. One of my very favorite leaves of all wildflowers is that of the Zigzag Goldenrod, S. flexicaulis, having very broad leaves. This is the only species that is able to grow in fairly shady woods and, in my estimation, is a downright elegant plant that is now in bloom and is very widespread in the county. The Zigzag Goldenrod is easily identified by its pronounced gently zigzagged stem and wide, beautifully shaped leaves with coarse teeth along their margins.

One of the rarest species of all wild plants in our state, thought to be found only along sandy shores in Door County and one other shore-bordering county in the state to the south, is the Dune Goldenrod, S. simplex, meaning simple and undivided. It is a federally and state-threatened plant requiring all the protection we can give it. It can be told by its narrow plume-like inflorescence and deep maroon-colored stem. It’s perhaps the last vigorous blossoming plant of the season nearest to Lake Michigan, usually well into October.

Eight to 10 weeks of glorious goldenrods in one county is nothing to sneeze at!