View photos of the edible plant, Perideridia parishii (Yampa), profiled in Wild Edible Plants of Arizona.

A passage from Wild Edible Plants of Arizona:

The seed, flower, leaf, and stem are eaten raw; however, the small tubers are the sought–after part. They lie just below the ground’s surface and are small: 1”–2” long by 1/2”–3/4” wide, with 1–2 tubers per plant being the norm. They are pleasantly crunchy (not fibrous) eaten fresh. I can’t seem to keep for eating them immediately, but I’m sure they too are a fine cooking candidate.