Sanicula canadensis

Sanicula canadensis, the Canadian blacksnakeroot, is a native plant of North America and a member of family Apiaceae. It is biennial or perennial, and spreads primarily by seed. It grows from 1 to 4.5 feet tall, and is found in mesic deciduous woodlands. The whitish-green flowers with sepals longer than petals, appearing late spring or early summer and lasting for approximately three weeks, are green and bur-like. The bur-like fruit each split into 2 seeds. The species ranges throughout the eastern United States (excluding Maine), extending north into Quebec and Ontario, and west into Texas and Wyoming....read more on Wikipedia.