What it is
Not actually rice — the seed of an aquatic grass, hand-harvested by canoe by the Anishinaabe of the Great Lakes. A gathered seed, not a Neolithic crop.
Why your biology objects
Closer to a wild-gathered food than a cultivated cereal, and higher in protein, lysine and minerals than true rice. Two honest footnotes: as an aquatic grain it takes up arsenic (more than white rice, less than brown — rinse and cook in plenty of water), and like any grass seed it benefits from soaking.