Culvers root

from WordNet (r) 3.0 (2006)

Culvers root
    n 1: a tall perennial herb having spikes of small white or
         purple flowers; common in eastern North America [syn:
         {Culver's root}, {Culvers root}, {Culver's physic},
         {Culvers physic}, {whorlywort}, {Veronicastrum virginicum}]

from The Collaborative International Dictionary of English v.0.48

Culver's physic \Cul"ver's phys"ic\, or Culver's root \Cul"ver's
root`\ [So called after a Dr. Culver, who used it.] (Bot.)
   The root of a handsome erect herb ({Leptandra Virginica} syn.
   {Veronica Virginica}) common in most moist woods of North
   America, used as an active cathartic and emetic; also, the
   plant itself.
   [Webster 1913 Suppl.]