Shakespeare, with his impressive knowledge of plants and their uses, might have looked on my yacon seedlings and said the above. I'm guessing that yacon hadn't made it to London by the 1590s or Stratford's finest scribbler would have mentioned it: "Why man, it doth bestride the narrow border like a colossus and we petty men walk under its huge branches and peep about.... Let me have about me roots that are fat". You get the drift. 
Fast forward a few centuries, stepping nimbly from doublet and hose into a zoot suit and let the good times roll with Louis Jordan. "Long, lean and lanky, ain't had nothing to eat" is his description of the eponymous protagonist in the 1945 hit Caldonia. That would apply equally well to my yacons. I've been waiting for the weather to warm up and lacking the necessary space to pot them on, they've got distinctly malnourished. Ain't that the truth! Well Louis, they're my babies and I love 'em just the same. I'm hoping that as soon as they get into the ground, they'll forgive me.
Comments
Vegetable Heaven - when your brain has recovered sufficiently, let me know what it reminds you of.
Frank - they probably did get a bit short of light. You're right, they seem to be much more vigorous than plants from tubers. I'm sure these would be almost full size by now if they'd had more space and bigger pots.
Jeremy - that must be a distinct possibility. Although I've never seen any obvious viruses in yacon, it's hard to believe that they aren't lurking in there somewhere.