The Root of the Alfalfa
A very prominent characteristic of the alfalfa plant is that it sends down a relatively gigantic root to really astonishing distances in search of water. This specimen is placed beside a twenty-four inch ruler. Note the rugged character of the root, and also the bends in it, which indicate where it was forced to make its way around a stone or some other obstacle.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 8 Chapter 3