The Collaborative International Dictionary of English v.0.48:
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. [1913 Webster]WordNet (r) 3.0 (2006):
Arundo donax n 1: large rhizomatous perennial grasses found by riversides and in ditches having jointed stems and large grey-white feathery panicles [syn: giant reed, Arundo donax]