Antennaria parlinii

Looks like dog fennel, Eupatorium capillifolium. It's a weedy native and not typically part of a seed package. My neighbor has a huge stand of it. Dog-fennel Thoroughwort (delawarewildflowers.org)

I still don't get the Blue Cohosh connection, based on the photos I looked at last night. The dangly yellow flowers bear no resemblance to the flower I photographed. But I appreciate being reminded of Name That Plant. I came to GardenWeb as an avid gardener quite a few years ago, but my gardening days are behind me, along with the many wonderful forums I frequented before. Yes, my daughter-in-law was with my grandson when he picked the flowers. I'll pass along the information about this plant. From Deadly Nightshade to rhubarb leaves, there's lots of things around here that should never go in mouths. But obviously, even after 40+ years here, I still don't know all of them. Thanks for your help, everyone!

I agree. Radish, or else something so closely related it *thinks* it's a radish, lol. I'm terrible about letting my radishes bolt instead of uprooting them and composting them before they go to seed, so I've seen many a radish bloom. But even without the bloom, the leaves are very indicative of radish.