Clusters of white yarrow flowers.
yarrow definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of a genus (Achillea) of perennial plants of the composite family; esp., the (A. millefolium), having a strong smell and taste, finely divided leaves, and clusters of small, pink or white flower heads
Origin: Middle English yarowe ; from Old English gæruwe, akin to German garbe
yarrow definition by American Heritage Dictionary
Any of several plants of the genus Achillea of the composite family, especially A. millefolium, native to Eurasia, having finely dissected foliage and flat corymbs of usually white flower heads. Also called achillea, milfoil.
Origin: Middle English yarowe, from Old English gearwe.