Queen Anne's lace

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

• noun A widely naturalized Eurasian herb (Daucus carota subsp. carota) in the parsley family, having finely divided leaves and compound umbels of small white flowers.

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

• noun A flowering plant, species Daucus carota, especially the flowering part of the plant.

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

• noun a widely naturalized Eurasian herb with finely cut foliage and white compound umbels of small white or yellowish flowers and thin yellowish roots