Source : Webster's Revised Unabridged Dictionary (1913)

Willow-herb \Wil"low-herb`\, n. (Bot.)
   A perennial herb ({Epilobium spicatum}) with narrow
   willowlike leaves and showy rose-purple flowers. The name is
   sometimes made to include other species of the same genus.

   {Spiked willow-herb}, a perennial herb ({Lythrum Salicaria})
      with willowy leaves and spiked purplish flowers.

Rosebay \Rose"bay`\, n. (Bot.)
      (a) the oleander. [Obs.]
      (b) Any shrub of the genus {Rhododendron}. [U.S.]
      (c) An herb ({Epilobium spicatum}) with showy purple
          flowers, common in Europe and North America; -- called
          also {great willow herb}.

Fireweed \Fire"weed`\, n. (Bot.)
   (a) An American plant ({Erechthites hiercifolia}), very
       troublesome in spots where brushwood has been burned.
   (b) The great willow-herb ({Epilobium spicatum}).