Loosestrife \Loose"strife`\, n. (Bot.)
   (a) The name of several species of plants of the genus Lysimachia, having small star-shaped flowers, usually of a yellow color.
   (b) Any species of the genus Lythrum, having purple, or, in some species, crimson flowers. --Gray.

Source: Webster's Revised Unabridged Dictionary (1913)