purple loosestrife

noun
  1. an Old World plant, Lythrum salicaria, of the loosestrife family, widely naturalized in North America, growing in wet places and having spikes of reddish-purple flowers.

Origin of purple loosestrife

First recorded in 1540–50
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018