"Banana Yucca Root is also called Spanish Dagger, or 'o-e-toctk' in Papago, is the deep red color in baskets.
Red baskets are prized by collectors because of their scarcity. Yucca root is more prevalent around the villages up off the desert floor with higher elevations like Quiotoa, Comobabi or Cababi.
To secure this material is a very laborious chore which entails digging up the roots with a pick, and then stripping them into this bands."
taken from Terry DeWald's The Papago Indians and Their Basketry