Chufus, Cyperus esculentus, also called chufa sedge, nut grass, yellow nutsedge, tiger nut sedge, or earth almond, seems to have been a sweet treat you could buy at the County Fair!!
Dried chufa has a smooth tender, sweet and nutty taste. It can be consumed raw, roasted, dried, baked or as tiger nut milk or oil.
Note at the end of the 1899 page the source for seed chufa is Buckbee's store.