aristolochia macrophylla

from WordNet (r) 3.0 (2006)

Aristolochia macrophylla
    n 1: hardy deciduous vine having large leaves and flowers with
         the calyx tube curved like the bowl of a pipe [syn:
         {Dutchman's-pipe}, {pipe vine}, {Aristolochia macrophylla},
         {Aristolochia durior}]

from The Collaborative International Dictionary of English v.0.48

Dutchman's-pipe \Dutchman's-pipe\ n.
   a hardy deciduous American vine ({Aristolochia durior})
   having large, heart-shaped leaves and bearing brownish-purple
   flowers which have their calyx tubes curved like the bowl of
   a tobacco pipe. Formerly classified as {Aristolochia Sipho}.

   Syn: pipe vine, {Aristolochia macrophylla}, {Aristolochia
        durior}.
        [1913 Webster + WordNet 1.5]