For the most part, we (or at least I) most often take notice of wildflowers while they’re blooming. The colourful blossoms are at their showiest, catching our attention. When I try to bring to mind exceptions, one that stands out is Common Milkweed, as the drifting seeds from the dried, split pods are difficult to miss, especially when illuminated by the low autumn sun. Common Mullein might be another, the stiff, woody stalks lasting long into the winter and often the following spring, eventually one of the few bits of meadow life still poking out above the deep beds of snow.
To that category I’ll have to add Thimbleweed, Anemone virginiana. These plants bloom during the summer months, June through August. We have, it turns out, quite a few of them scattered randomly through our fields, and a number of them grow not too far from the trail that cuts through the grass. And yet, during the summer I don’t recall even once making a note of the plants. It’s only been since the flowers have died and the seed heads developed that they drew my eye.
The deeply sharp-lobed leaves at the base of the plant, and the evidence of similar (though now dead) leaves partway up the stems, told me this was an anemone, and a bit of poking around reveals it to be Thimbleweed (sometimes clarified as Tall Thimbleweed to distinguish it from the similar Long-fruited Thimbleweed). The name, of course, comes from the seedheads which do look an awful lot like thimbles, and are about the right size as well. When flowering they have typical anemone blossoms, five-petaled and white, pretty but unassuming, which is perhaps how I missed them all summer.
Anemones are generally woodland plants, but some, including Thimbleweed, can be found growing out in the open, though usually within sight of the woods. It seems to have a preference for dry habitats, but is adaptable and will also grow in moist soil. As the fall progresses, those thimble-like seedheads will open up, releasing puffs of cottony seeds, not dissimilar to those of milkweed and dispersed by the same means.
Interestingly, the plant isn’t often eaten by mammalian herbivores because the leaves contain a compound that can blister the inner membranes of the mouth and stomach. Perhaps the same chemicals that cause this made it useful to Native Americans as a medicinal plant, used as an expectorant (thins mucus so it can be more easily coughed up), an emetic (triggers vomiting), and an astringent (shrinks body tissues to reduce swelling or irritation). Smoke from burning the seed pods was also used like smelling salts, to revive the unconscious.
seabrookeleckie.com 
Very interesting information of how native Americans used this plant. I wonder if pharmaceuticals are using it in some way? — barbara
I love this plant. The texture of the seed “fuzz” is just wonderful. Definately a fun plant to point out to children on nature walks.
I noticed this plant for the first time a few days ago! The seed pod has marvelous texture…
Thanks for commenting, everyone!
And I don’t know, Barbara, but I would suspect not. Or, not anymore. My impression is that these days, most of our medicines, etc, are synthetically produced, though there are still some big brands (eg. Preparation H, which is almost purely shark liver oil) that use natural ingredients.