Definition of "rhizome"

All these species are climbing, briery plants, having long slender roots, which proceed in all directions from a common rootstalk or rhizome.

1868, George Bacon Wood, A Treatise on Therapeutics, and Pharmacology, Or Materia Medica, Philadelphia: J. B. Lippincott & Company, page 432

The corpus of Kafka's writing, they argue, is ‘a rhizome, a burrow’ (K 7)—an uncentered and meandering growth like crab grass, a complex, aleatory network of pathways like a rabbit warren. A rhizome, as Deleuze and Guattari explain in Rhizome: an Introduction (1976), is the antithesis of a root-tree structure, or ‘arborescence’, the structural model which has dominated Western thought from Porphyrian trees, to Linnaean taxonomies, to Chomskyan sentence diagrams.

1989, Ronald Bogue, Deleuze and Guattari, Psychology Press, page 107

Critical theorists have often drawn from Deleuze and Guattari's notion of the rhizome when discussing the potential of the Internet. While the Internet may structurally appear as a rhizome, its day-to-day usage by millions via search engines precludes experiencing the random interconnectedness and potential democratizing function.

2008, A. Hess, “Reconsidering the Rhizome”, in Amanda Spink, Michael Zimmer, editors, Web Search: Multidisciplinary Perspectives, Springer Science & Business Media, page 35