Cyperus esculentus, a nutty tasting dried tuber grown predominantly in Spain. Chufas originated from the Nile River Delta in Egypt and were later taken to Spain by the Phoenicians. In Spain the tubers (referred to as nuts) are dried and ground to make a drink called Horchata. (See recipes). The dried nuts can also be eaten as a snack.
The chufa nuts are easily ground into a flour. In addition to be the key ingredient in horchata, the flour can be used in most recipes that call for almond flour. The chufa is not really a nut so the flour can be eaten by people with nut allergies. The flour has a pronounced sweetness so it works best in sweet rather than savory recipes.