rhizome (n.) Look up rhizome at Dictionary.com
1832, from Modern Latin rhizoma, from Greek rhizoma "mass of tree roots," from rhizoun "cause to strike root, root into the ground, plant," from rhiza "root," probably from PIE *wrad- "branch, root" (cognates: Latin radix "root," Old Norse rot "root," Old English wyrt "plant, herb;" see radish).