Tractor roots! I love it!
Yes, we all know there are tiny tiny nano-tractors working below the soil surface. John Deere if they are employed by American lilies, Toyota if Japanese. European lilies use Fendt or Husqvarna. Russian, Siberian and Caucasian lilies prefer to dig their way down rather than pull, so they use Chetra machinery.
Kidding aside, what Wanda meant to say was
contractile roots, not tractor roots. Some people have 'senior moments"; others have "machinery moments".
(Edited out Moby's name.)