Becketwood Cooperative
An Active, Independent 55+ Community of Owners in Minneapolis

All Those Yellow Flowers

By Naomi Jackson, Becketwood Member

August 2021

The west end of Fernwood Glen is blanketed with yellow flowers, to the delight of bees, leatherwing beetles, and the spiders that eat them. And us. We say to each other, “Look at those black-eyed Susans!” But did you know that we have six species of yellow wildflowers in Fernwood Glen? And have you ever wondered who Susan is?

If you've walked through the glen, you know that I like to label the wildflowers. But for three summers the yellow flowers had me stymied. I knew they weren't all the same species (obviously; the cup plants are seven feet tall!). But trying to identify them all by their common names only led to confusion. Is that a brown-eyed Susan or black-eyed Susan? Sweet coneflower, or thin-leaved coneflower? Green-headed coneflower, or cut-leaf coneflower?

Last summer I realized that I had to switch to using the system developed by Carl Linnaeus in the 18th century: binomial nomenclature (system of naming using two terms). You may remember in high school biology memorizing “Kingdom, Phylum, Class, Order, Family, Genus, Species.” For example, humans, who like to classify things, are Animal, Chordate, Mammal, Primate, Hominidae, Homo, Sapiens. Generally, we only use the last two categories, Homo sapiens, which are like a last and first name. The names are italicized because they are from another language, Latin.

Nearly three centuries after Linnaeus, there is a growing realization that there are problems with his system: the definition of “life” is not as rigid as we thought; species don't behave the way we think they ought to; the concept of “newly discovered” usually means newly discovered by White Europeans; and trying to categorize everything is like trying to put the round earth in a square hole. Still, binomial nomenclature is useful because it helps scientists communicate across cultures and languages. And it helped me to sort out all those yellow flowers.

When sorting out who's who, it's helpful to know that “coneflower” refers to a characteristic of a plant, not a species of plant. It means that the center part of the flower sticks up noticeably above the petals.

Four of our yellow flowers belong to the genus Rudbeckia, which is named after a Swedish father and son, O. J. and O. O. Rudbeck, who were professors of botany. For each flower, the name following Rudbeckia is the species name, for which I've given you the definition.

Rudbeckia hirta: Their common name is black-eyed Susan and they are sturdy and drought-resistant. Hirta refers to their hairy stems and leaves. They are by far the most abundant Rudbeckia in Fernwood Glen and sometimes need to be kept under control.

Rudbeckia triloba: The lower leaves have three lobes, thus the name triloba. They are commonly called brown-eyed Susan, three-lobed coneflower, or thin-leaved coneflower. They are easy to identify because their petals are rounded at the end rather than pointed.

Rudbeckia subtomentosa: Called sweet coneflower or sweet black-eyed Susan, the leaves of this yellow flower are densely hairy (tomentosa) but not as much as other Rudbeckias (sub). In fact, the leaves seem quite smooth compared with R. hirta. There is only a small patch of sweet coneflower in Fernwood Glen, snugged up against the cup plants.

Rudbeckia laciniata: The leaves of the cut-leaf or green-headed coneflower are fringed or very deeply cut, thus the name laciniata, torn or slashed. It is much taller than the other Rudbeckias, 4 to 6 feet, and the petals are a paler yellow. We have two clumps in the pond area.

The other two yellow flowers are in different genuses (genera):

Heliopsis helianthoides: There are only two smooth oxeye plants in Fernwood Glen, and they have really struggled in the drought. Watch for them on the right as you walk from the back bench toward the open (pond) area. Helianthoides means “like a sunflower,” but they aren't true sunflowers. Their center is mostly yellow and flat, distinguishing them from those other yellow flowers.

Silphium perfoliatum: The cup plants, on the far west of Fernwood Glen, have done well in the drought despite not being watered at all. They are seven to eight feet tall and the stems grow through the leaves (perfoliatum means “through the leaves”) forming cups that hold water. These are popular with insects and small birds. Chipmunks like to climb the sturdy stems to harvest the seeds. Like the black-eyed Susans, cup plants will take over if you let them.

All these yellow flowers, along with purple coneflowers, asters, sunflowers and daisies, are members of the family Asteraceae (Aster) which means “star.” So imagine, as you admire them, that they are stars fallen to earth to bring us joy.

P.S. There's still a mystery: Why the name “Susan?” A common explanation is it's from an old British poem, “Sweet William's Farewell to Black-eyed Susan” by John Gay. But no one really knows.





Leave a Reply

  • Anonymous August 18, 2021, 5:08 pm

    So educational! And a gorgeous photo.

  • Helen Gilbert August 18, 2021, 10:43 pm

    Thanks, Naomi, for bringing this sunshine into my day!

  • Judy August 19, 2021, 2:54 am

    Even with drought Fernwood Glen is showing off. Thanks for your comments.

  • Carol August 20, 2021, 12:23 am

    Your nonscientist friend whose favorite color is yellow thanks you. Also for all your work out there.

  • Sally Lofte August 30, 2021, 6:52 pm

    Enjoyed reading this most interesting blog and informative blog!
    Thanks for researching this and sharing with us…