Geum macrophyllum

Geum macrophyllum, commonly known as largeleaf avens or large-leaved avens is a flowering plant found from the Arctic south to the northern U.S. states, and in the Rocky Mountains and west to the Sierra Nevada in California and as far south as Northwestern Mexico.

It is even more distinctive in fruit than in flower, with spiky spheres of reddish styles. The fruits are a ball of tiny velcro like hooks that catch on clothing and animal hair.