The Collaborative International Dictionary of English v.0.48:

Maranta \Ma*ran"ta\, prop. n. [NL.] (Bot.)
   A genus of endogenous plants found in tropical America, and
   some species also in India. They have tuberous roots
   containing a large amount of starch, and from one species
   (Maranta arundinacea, the American arrowroot or obedience
   plant) arrowroot (arrowroot starch) is obtained. Many
   kinds are cultivated for ornament.
   [1913 Webster]

WordNet (r) 3.0 (2006):

maranta
    n 1: any of numerous herbs of the genus Maranta having tuberous
         starchy roots and large sheathing leaves