Name: Jeanie Minnesota (Zone 4a) Replace your lawn with a garden!
Just following up - the plant was definitely NOT astrantia, it was mugwort, and I dug the whole thing up and tossed it. Thanks for questioning this; I kept a watch on it and would have had an invasive thug on my hands had I let it go.
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Old gardeners never die. They are just pruned and repotted.