Although I have never eaten the Maximillan Sunflower tuber, I do grow and eat the root tuber from a related plant, another native sunflower, Jerusalem Artichoke or Helianthus tuberosus.

"Supplementary watering in prolonged dry conditions enhances yield." Sunchokes (Helianthus tuberosus), also known as Jerusalem artichokes, grow from tubers, which store water. Additionally ...