Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
any of various knotgrasses (genus Polygonum) whose acrid juice may cause skin irritation
Used by arrangement with John Wiley & Sons, Inc.
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Any of various marsh plants of the genus Polygonum, having sheathlike stipules and small, densely clustered pink, white, or green flowers.