Tiger Nuts

Cyperus esculentus (chufa sedge, yellow nuts edge, tiger nut sedge, earth almond) is a species of sedge native to warm temperate to subtropical regions of the northern hemisphere, often cultivated for its edible tubers (tiger nuts). It is an annual or perennial plant, growing to 90 cm tall, with solitary stems growing from a tuber. The stems are triangular in section, and bear slender leaves 3�10 mm wide. The flowers of the plant are distinctive, with a cluster of flat oval seeds surrounded by four hanging, leaf-like bracts positioned 90 degrees from each other. The plant foliage is very tough and fibrous, and is often mistaken for a grass.
There are several varieties:
cyperus esculentus var. Esculentus - mediterranean region east to india
cyperus esculentus var. Hermannii - florida
cyperus esculentus var. Leptostachyus - united states
cyperus esculentus var. Macrostachyus - united states
cyperus esculentus var. Sativus - asia, cultivated origin
history
zohary and hopf consider this tuber "ranks among the oldest cultivated plants in ancient egypt." although noting "chufa was no doubt an important food element in ancient egypt during dynastic times, its cultivation in ancient times seems to have remained (totally or almost totally) an egyptian specialty. They were used to make cakes in ancient egypt. Presently, they are cultivated mainly, at least for extended and common commercial purposes, in spain, where they were introduced by arabs, almost exclusively in the valencia region. They are found extensively in california and were grown by the paiute in owens valley.