Using DG for a native plant ID: Late-flowering Boneset (Eupatorium serotinum)
(Editor's Note: This article was originally published on September 14, 2008. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)
A few years ago, I found I had the time and inclination to learn more about plants and gardening. I checked out library books and "googled" my plants on the computer. Every time I searched the Internet for information on some pretty flower, the results led me to Dave's Garden. Boy, was I grateful for my ten free daily searches of PlantFiles, where thousands of gardeners had entered information on more thousands of purchased plants. Not all of my plants came with glossy tags or pretty packets though. I also wanted to learn about the native plants that were volunteering in my yard--those wild things that sprouted here and there, taking advantage of my lazy weeding ways. So with a budding interest in native plants, I tried to familiarize myself with the little beauties planting themselves in my flowerbeds.
Many of those native babies look maddeningly indescript. Here's one of my more promising looking seedlings. A certain pleasant symmetry and sturdiness caught my eye, but this juvenile would have to mature for enough identifying characteristics to show. I let it grow. Over the summer, no flowers appeared but the young sprout grew into a sturdy, bushy plant with bluish-green, long, pointed leaves. Finally, at the very end of August, the three- to four-foot stems were topped by a frost of white buds. Flowers arrived in the form of open heads of tiny fringed blooms. Wasps, bees, beetles, and small butterflies loved this plant! And though it wasn't visually spectacular, I would catch a whiff of perfume whenever I passed by on warm, late-summer days.
Now that this particular volunteer had shown a few nice qualities, I was driven to properly name it. I paged through my Audubon Society Field Guide to North American Wildflowers, and The Illustrated Book of Wildflowers and Shrubs (of Eastern North America). I focused on another late-summer bloomer called boneset. My plant didn't exactly match its description. But I felt pretty certain that my mystery native came from the same group of plants as boneset, a group properly named as the genus Eupatorium.
Feeling semi-smart with my narrowing down of ID, I crossed my fingers and posted a picture and short description of "Mid Atlantic Eupatorium" on Dave's Garden Plant and Tree Identification Forum. Finger-crossing worked--pretty soon a friendly fellow gardener replied. KSBaptisia suggested that my plant was properly known as Eupatorium serotinum and commonly called "late-flowering boneset." He added a link to Missouriplants.com for more help in confirming the plant ID.
Now, before following that link, I used the new-found Latin name and searched "old reliable" PlantFiles. I was slightly surprised by what I found. No, I was surprised by what I didn't find. The PlantFiles listing for Eupatorium serotinum contained only the barest information, which was an interesting twist. If I could confirm my plant as Eupatorium serotinum, I would be able to PROVIDE all those details to PlantFiles, from my own observations! Wow, I could be a real contributor to, instead of just a consumer of, Dave's PlantFiles.
So on to the website suggested to me, Missouriplants.com. I found it to be incredibly helpful and loaded with pictures and details on native plants. Even though Missouri is about a thousand miles away from my home, we share a lot of native plant species. Several color pictures looked exactly like the plants I'd been watching in my yard. But I didn't want to rely on my comparison of photographs alone. I worried that I could still misname my plant because of my lack of expertise. So I turned to the technical descriptions of the plant. And I stopped short. There were some technical terms all right--words I'm pretty sure I never even heard in Botany 101. I was briefly worried that I couldn't decipher these detailed descriptions.
A few of the many visitors to Euparotium serotinum
I wasn't going to quit yet. Aha! How about Dave's Garden Terms and Botanary ? Those are two great places for anyone to look up strange words or phrases that they see used in garden writing of any scope. Sure enough, I found definitions for phyllary, floret, and pappus--words I needed to understand to decipher the description of my boneset. ( I also found out that "serotinum" means "late-flowering"--I guess Latin isn't that weird after all.) Armed with new knowledge, I studied the description again and decided that I did actually have late-flowering boneset. I gathered a few choice plant parts and took clear, close-up photographs of the flowers. Just to be really sure about this name, I returned to my previous Identification thread and asked for a second opinion. Guess what? KSBaptisia confirmed for me that the pictures showed "involucral bracts" (little scaly things around the base of the tiny buds) that were "imbricate" (overlapping). ID confirmed!Knowing my plant's name allowed me to read a bit more about its background. MIssouriplants.com calls it one of Missouri's most common "weeds" and "definitely" its most common Eupatorium. When it's in bloom in September it seems to be along every road in Maryland, too. "Late-flowering thoroughwort" is another name used for this plant in some references. Although it has loads of flowers, this plant isn't included in my two wildflower books. The flowers are not quite showy enough to earn late-flowering boneset an entry into these books. It sure seems like an important plant for a huge assortment of big, little, tiny and tinier insects that come for the nectar like...well, like bees to honey. I spent more time editing these pictures of insects on my serotinum than I spent outside taking the pictures. The Eupatorium genus has a few members in the ranks of cultivated plants, such as the cultivars of Joe Pye Weed and White Snakeroot.
Will we see late-flowering boneset in the local nursery anytime soon? I don't think so. The bloom is not as full and attractive as that of white snakeroot or Joe Pye Weed. I keep a few specimens in my yard. I don't grow them in the front yard where I try to maintain suburban sensibility. My late-flowering boneset is in the back yard, where I can pass by a dozen times during my yard work and inhale the sweetness. I can walk out on dewy September mornings to dump coffee grounds and visit the wasps and hairstreak butterflies. But I'll be saving room for my Eupatorium serotinum. Not only is it free, it'll remind me of how I put together another piece of my backyard ecosystem puzzle and added to Dave's Garden at the same time.
More users of serotinum- compare the flowers to see relative size of the insects and spiders
Most field guides will have sketches and descriptions to help you learn the plant parts you need to know for identification.
You may enjoy the Botany for Gardeners articles by Dave's writer LariAnn Garner.
With my interest in native plants, I should probably visit the Native Plants and Wild Plants forum (please note, subscribers only) in Dave's Garden.
Niering, William A and Nancy C. Olmstead. The Audubon Society Field Guide to North American Wildflowers (Eastern Region). New York, Alfred A Knopf, 1979.
Grimm, William Carey. The Illustrated Book of Wildflowers and Shrubs (of Eastern North America). Mechanicsburg, Stackpole Books, 1993.