bur marigold

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several weeds of the genus Bidens of the composite family, having yellow flower heads and barbed achenes that stick to clothing or fur.

from The Century Dictionary.

• noun A bookname for the more showy species of Bidens.

from the GNU version of the Collaborative International Dictionary of English.

• See beggar's ticks.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A plant, the beggar's ticks.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any of several plants of the genus Bidens having yellow flowers and prickly fruits that cling to fur and clothing