In a recent post entitled Week 3: Rhizomatic or biological neuralogical network?, my colleague in CCK12 Matt Bury writes that he's "been pondering the analogy of distributed networks of learners, i.e. Connectivism, as rhizomes" and concludes that he "wasn’t convinced by it from the start." You can read the rest of Matt's thoughtful comments on his blog, but if I understand him correctly, he doesn't see a tight fit between botanical rhizomes and networks of people. Actually, he seems to prefer neurological networks, which appear to be structured much more like social learning networks. I, too, have found neural networks to be most helpful in understanding networks in general and neural networks in particular, and I heartily refer interested scholars to Olaf Sporns' book Networks of the Brain.
Matt makes a fair point that others have made: the Deleusian rhizome doesn't match so well with botanical rhizomes which don't match so well with social networks. I see Matt's point, and I think it has some substance, but for me, it is somewhat beside the point for several reasons. First, Deleuze and Guattari use the rhizome mostly as a metaphor, or so it seems to me, and I don't think metaphors can be pushed to any great precision. Rather, a metaphor compares a more tangible thing to another less tangible thing to illuminate some aspect of the second thing, or sometimes both things. Love is a rose is a metaphor that suggests certain features of love that we might not have thought about before; however, if we press the metaphor too closely, we can quickly discover features of love that are not like a rose and vice versa. Metaphors shift our point of view so that we look at an object differently than has been customary. It doesn't map to the second thing precisely.
Then Deleuze and Guattari do not rely so much on any botanical definition of rhizomes; rather, they describe the rhizome as a linguistic and social structure mostly, providing a definition of sorts based on six features: connectivity, heterogeneity, multiplicity, asignifying ruptures, cartography, and decalcomania. I'm no botanist, but I don't think these features are prominent in any definition of botanical rhizomes. For example, Deleuzian rhizomes are heterogenous. Most botanical rhizomes are homogenous. Rather, these features describe much more closely the way language develops and spreads, and Deleuze and Guattari use them that way.
I have found Deleuze and Guattari's rhizome to be a particularly potent metaphor that has given me a new way of thinking about social networks and a new vocabulary to use in discussing those networks. The metaphor may not work for everyone, however. Love is a rose no longer works very well for most people, though at one time, it was quite the fresh and striking image.
I'm not sure why Deleuze and Guattari chose the rhizome upon which to construct their analysis. I think it was the visual features that appealed to them, but that's just conjecture. Or perhaps they wanted another botanical image to contrast with the tree image that they were using to describe hierarchical structures (another metaphor, and again, not so precise as some trees such as aspens could be classified as botanical rhizomes—a detail Deleuze and Guattari ignore or are unaware of). Anyway, I think the point I've been wandering toward is this: when we speak of the Deleuzian rhizome, or rhizomatics, we are not speaking of a botanical rhizome, but of a metaphor for that undifferentiated ground of being out of which structures emerge and into which all structures eventually return. To scale that down to something more practical, we are talking about how we humans are constantly trying to map a shifting landscape—to capture in language, mathematics, and social, political, religious, and economic structures those details of reality that for a time seem important, but which always shift away from our names and structures into something else. If that is how the complex world works, then how do we educate for that? That's rhizomatic learning.