to my understanding, tapioca is a tropical tree and I wonder you have that tree in california? Tapioca or cassava (Manihot esculenta) can be consumed from the root (either boiled or fried) or the shoot (normally boiled or mixed with gravy)

refer to the link for further info

"The basic procedure for farina production is simple: the cassava is peeled, grated, and allowed to ferment for about 1-2 days when water is extracted by compression of the mash, then roasted. Farina is produced throughout the country, especially in Bassa, Bomi and Nimba counties."

http://www.fao.org/Wairdocs/ILRI/x5458E/x5458e0i.htm