Source : Webster's Revised Unabridged Dictionary (1913)

Donax \Do"nax\, n. [L., reed, also a sea fish, Gr. ?.] (Bot.)
   A canelike grass of southern Europe ({Arundo Donax}), used
   for fishing rods, etc.

Source : WordNet®

Arundo donax
     n : large rhizomatous perennial grasses found by riversides and
         in ditches having jointed stems and large gray-white
         feathery panicles [syn: {giant reed}]