"To make a prairie it takes a clover and one bee," wrote 19th century American poet Emily Dickinson. "One clover, and a bee, and revery …"
As a naturalist, I love Dickinson's poems about the natural world. At the same time, I am plagued by the naturalist's Scientific Curiosity Syndrome (SCS). When I read these lines, the question pops in my head, "Which species of clover? What kind of bee?"
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Indulging a bit in this curiosity, let's take a look at the clovers in the Prairie State and see if clovers do, in fact, make a prairie.
White clover is the first flower we learn as kids (along with dandelion). It's in the lawn, it's pickable, and it's pretty. Many generations of little girls have made floral crowns and necklaces by tying together the long stems of white clover.
White clover flowers are bunched together in a bouquet at the end of a single stem. If you look closely you'll see that each flower is shaped like a garden-variety pea blossom. Like the garden pea, white clover is in the legume family.
The scientific name for white clover is Trifolium repens, but it answers to other names as well. One name is Dutch clover. T. repens was domesticated in the Netherlands, but its origins are in the Mediterranean region. Repens means creeping. You may have dealt with the creeping habit of white clover as it spreads everywhere across your lawn.
A close relative of white clover is red clover, Trifolium pratense. The Latin descriptor pratense means "from the meadow." That's right where you'll find this plant -- in meadows, old fields, pastures, and waste places.
The genus name Trifolium refers to the three leaves of these clovers. Finding a four-leaf clover is said to be good luck -- but you'll be hard pressed to find a four-leaved Trifolium.
Numerous species of Trifolium have been naturalized in temperate regions throughout the world. They were transported from their Eurasian home to every continent except Antarctica for use as forage and cover crop. They help improve the soil by their ability to "fix" nitrogen -- that is, to make it available to plants. Their root systems also help to hold soil and prevent erosion.
Two other common clovers in Illinois are white and yellow sweet clovers. Some would say these are too common, and not-so-sweet. Melilotus is the sweet clover genus, and the two species are alba, with white flowers, and officinalis, with yellow flowers.
These robust, bushy plants can grow to eight feet tall. Like white and red clover, they were introduced to North America from Eurasia for forage. The flowers are favorite nectar sources for honeybees, so beekeepers welcome sweet clovers in their fields.
All of these Old World clovers have a long history of medicinal and cultural uses. Whether used as infusions for fevers or eyewash, in tea for coughs, or in poultice for paralysis, clovers were an ancient cure for what ailed you. There were spiritual applications as well.
Nineteenth-century botanist M.T. Masters wrote in 1869 that red clover "was gathered at nighttime during the full moon by sorceresses, who mixed it with vervain and other ingredients, while young girls in search of a token of perfect happiness made quest of the plant by day."
A less dubious use of sweet clover is in the cheese industry. In Switzerland, sweet clover is added to curd in the process of making an artisan cheese known as Schabzieger.
The sweet clovers have their virtues, but they are full of vice as well. Both species are aggressive, and they readily invade open, sunny areas. They're winter hardy and drought tolerant. They're prolific seeders.
According to the North Dakota State Library website, one sweet clover plant can produce more than 100 seeds. The seeds germinate readily in full sun. Those that don't germinate immediately are viable in the soil for more than two decades.
Fire, a commonly used management tool to fight back aggressive weeds in native prairies, only encourages these clovers. They often grow vigorously after prairie burns. Thus, the tenacious sweet clovers displace native prairie plants wherever they grow.
There are lots of nonnative clovers, but are there any that actually belong in a prairie? Yes! There are some great native clovers. And while Emily certainly earned her poetic license, we know that to make a prairie it takes not just any old clover, but the native ones.
Indigenous to our prairies are the true "prairie clovers" (are these all starting to sound the same?). The genus Dalea is represented by several species, most notably purple prairie clover (D. purpurea).
This brightly-colored prairie clover is in full bloom this week in Kane County prairies. Bright magenta flowers ring the lower half of a central head. The entire flower head resembles a little purple tutu. White prairie clover (D. candidum) is not as common as purple prairie clover, but it too sports the skirt.
A third species called leafy prairie clover (D. foliosum) is extremely rare. According to Plants of the Chicago Region by Floyd Swink and Gerould Wilhelm, leafy prairie clover is "one of America's rarest plants, and thought to be locally extinct until its rediscovery by [Wilhelm] in 1974."
There is a record of leafy prairie clover in Kane County, but finding this plant would be a "eureka!" experience.
Finally, there are bush clovers. These belong to the genus Lespedeza. You're likely to find the round-headed bush clover (L. capitata) in our local prairies. This tall plant likes it dry, often growing in sandy or gravel soil. The modest cream-colored flowers lack the wow-factor of purple prairie clover, but round-headed bush clover is a fine native prairie plant. Its peak flowering time is late summer to early fall.
There's a whole world of clovers out there. Each kind is useful, and each is pretty in its own right. The next time you walk in a field, look around and you'll surely see a clover or two. Add a bee and some reverie -- and Ms. Dickinson will smile from above.
• Valerie Blaine is a naturalist with the Forest Preserve District of Kane County. You may reach her at firstname.lastname@example.org.