canna edulis

from WordNet (r) 3.0 (2006)

Canna edulis
    n 1: canna grown especially for its edible rootstock from which
         arrowroot starch is obtained [syn: {achira}, {indian shot},
         {arrowroot}, {Canna indica}, {Canna edulis}]

from The Collaborative International Dictionary of English v.0.48

Tous-les-mois \Tous`-les`-mois"\, n. [F., all the months, i. e.,
   every month.]
   A kind of starch with very large, oval, flattened grains,
   often sold as arrowroot, and extensively used for
   adulterating cocoa. It is made from the rootstocks of a
   species of {Canna}, probably {Canna edulis}, the tubers of
   which are edible every month in the year.
   [1913 Webster]