The Collaborative International Dictionary of English v.0.48:

Tuckahoe \Tuck"a*hoe\, n. [North American Indian, bread.] (Bot.)
   A curious vegetable production of the Southern Atlantic
   United States, growing under ground like a truffle and often
   attaining immense size. The real nature is unknown. Called
   also Indian bread, and Indian loaf.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tuckahoe
    n 1: perennial herb of the eastern United States having
         arrowhead-shaped leaves and an elongate pointed spathe and
         green berries [syn: green arrow arum, tuckahoe,
         Peltandra virginica]