I have had good success with Xanthosoma sagittifolium as a root crop. Common english name is Tannia, common Spanish names are malanga or Yautia. This is different from Taro which is Colocasia esculenta. The Xanthosoma is a native american plant, takes much longer than the large taro and needs far less water. It also keeps in the ground much better. You can eat the cormels like potatoes, and even the large 4 inch diameter stems are edible. They work in fairly shady spots within fruit tree areas but just outside the canopy. I got a start with grocery store cormels but within a few years I have unlimited planting material at any time.
The big advantage is they are available year round and can be dug and used whenever, versus cassava which goes bad quickly after harvest or gets hard if left too long in the ground, or yams which have limited dormancy and are unavailable mch of the year.
The second best new staple I am growing is an edible Dioscorea bulbifera yam. This came from India originally but mine was sent from Puerto Rico. This is a completely edible type of "air potato" which is the bane of Florida, except is an edible form, very smooth skin and good eating. While seasonal the same as other yams this one is perennial in the ground and you never have to dig the "mother", just pick the potatoes off the vine. I put in a 100 ft row on a fence last year.