Sunflower family member has medical uses and more | Mystery Plant

“'Cause I live and breathe this Philadelphia freedom/ From the day that I was born I've waved the flag …” Elton John, Bernie Taupin, "Philadelphia Freedom"

All the "composites," or members of the sunflower family (or aster family, if you prefer), have their tiny, reduced flowers arranged in compact heads, and each head is called a “capitulum.” Before the capitulum opens, a series of bracts surrounds it, much like the sepals surround a flower bud before it opens up.

When it blooms, the head will have this series of bracts all tucked down at the bottom, revealing the tiny flowers above. Of course, the take-home message of all this is that a single head is not just one flower. It’s several, sometimes a great many.

Thus, when you pick a daisy, or a sunflower, you are actually holding about 100 flowers (give or take), not just one flower.

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Most composites tend to bloom, as a group, later in the year. Goldenrods, sunflowers, joe-pye weeds and asters come to mind quickly as prominent fall-bloomers. Other members, such as the coneflowers and tickseeds, are at their height during the summer months.

And what about everybody’s favorite hay-fever plant, ragweed, which is indeed a member of the sunflower family, and which starts to bloom in the summer?

Of course, there are several different kinds of dandelions and dandelion-like species (mostly weeds), and some other, mostly introduced composites that bloom early, such as the charming “Bachelor’s buttons” (Centaurea cyanus), which you sometimes find growing along the railroad tracks and field margins.

Our Mystery Plant — daisy fleabane (Erigeron philadelphicus) — is a native species that has been making quite a show.

Daisy fleabane is found in a variety of places, mostly not very special ecologically, and it can be rather weedy. It can be found in most of Canada and every one of the United States, though not so commonly in the desert Southwest.

Its buds will open up, first revealing bright white ray flowers (the narrow flowers on the outside edge of the head), with golden-yellow disk flowers opening in the interior. The rays commonly become lighter, often changing from white to pale pink or lavender.

Its fruits are tiny little achenes, each with a fluff of snow-white bristles at the top. (The fluffy stuff, which allows wind-transport, is called the pappus. The genus name means “early old man,” an allusion to an old man’s hair and beard.)

Carl Linnaeus described this plant in 1753, based upon a specimen that he received from his student, Peter Kalm, who collected plenty of specimens from America. Not knowing too much about the geography, Linnaeus indicated in his text that the plant grows in Canada (which is true), but he named it after the city of Philadelphia — which was at the southern end of his own concept of “Canada.”

Daisy fleabane has been used medicinally for quite a number of ailments, and a rather longstanding tradition maintains that the foliage will keep fleas away. That's why this species (and its close relatives) have sometimes been used, after drying, for stuffing mattresses. Hope you won't have to use it for that, though.

John Nelson is the retired curator of the A.C. Moore Herbarium at the University of South Carolina in Columbia, S.C. As a public service, the Herbarium offers free plant identifications. For more information, visit www.herbarium.org or email johnbnelson@sc.rr.com.