A burdock burr is covered in tiny curved hooks — ChillScroll

Round burdock burrs with tiny curved hooks caught in soft golden dog fur

A burdock burr is covered in tiny curved hooks

After the flowers dry, hooked bracts surround the seeds. The hooks catch on fur or clothing, carry the burr to a new place, and later inspired the hook-and-loop design of Velcro.

The burr gets a ride; the traveler gets a very clingy souvenir.

Source · University of Illinois Extension ↗