View photos of the edible plant, Cyperus esculentus var. leptostachyus (Yellow nutsedge), profiled in the Wild Edible Series: Arkansas, California: Vol 1,  Louisiana, Oklahoma, and Texas: Vol 1.

A passage from Wild Edible Plants of California:

Yellow nutsedge (like nearly all Sedge family plants) has 3–ranked leaves and 3–angled stems. Use these characteristics to help distinguish it from look–alike grasses.

A passage from Wild Edible Plants of Texas (Vol 1):

Yellow nutsedge produces small (size–variable) edible tubers (tuberiferous stolons). They are easy to gather
with a trowel due to the plant’s tubers not being far below the surface.

View photos of the edible plant Cyperus fendlerianus (Fendler’s nutgrass), profiled in Wild Edible Plants of Arizona.

A passage from Wild Edible Plants of Arizona:

Each stem is anchored by a shallow cluster of fibrous roots. Attached to the small root crown are one to several (usually) corn–kernel sized bulblets (I call them niblets). These starchy and mild–sweet tasting pieces are fine consumed raw – after cleaning them up a little by scraping off their external–brown protective layer.