The cocklebur has an oval brown bur with hooked spines that produces two seeds in late season and is often confused with the bi-annual burdock (Arctium minus) which has a round bur and, in my opinion, softer spines.
The flower of the cockle is green and small / the flower of the burdock is purple and held on a tall stalk.
Cocklebur is toxic to pasture anamals
Cocklebur can be best controlled in the pasture by short mowing. It is an annual and reproduces only by seed.

Reply to this comment

This grows natively in the Black Hills. It is a very annoying plant, indeed. Makes walking through the forest a real hassle, because you have to worry about all the burrs you'll get stuck in your shoes and clothes. Big black ants are attracted to it, and every year they swarm all over the plant.

Reply to this comment