Leafy spurge (Euphorbia virgata)
https://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/leafyspurge.html

Leafy spurge. Photo: Peter M. Dziuk

Leafy spurge. Photo: Amy Rager

Leafy spurge flower. Photo: Andy Birkey

Leafy spurge plants. Photo: Katy Chayka

A small colony of leafy spurge. Photo: Katy Chayka