chufa Cyperus esculentus, a sedge common in S. Europe and Africa, has small, edible tubers a little less than 20 mm (just over 0.8") in diameter. These are black, with a nutlike texture and a sweetness which increases when the tubers have been stored for a few weeks and become slightly wrinkled. Their resemblance to nuts accounts for many of their common names including nut grass, tiger nut, earth almond, and earth nut. Chufa itself is a Spanish dialect name.
The same genus, Cyperus, embraces many common plants of boggy places all over the world, including several others with edible tubers; and also the Egyptian papyrus rush (nut), C. papyrus, from which the ancient Egyptians made their writing paper. A near relative is the larger and better-known Chinese water chestnut.
