I knew part of this but not all of it. I knew it was a seed and that
we eat it like a grain but I didn't know the rest of the story ...
Quinoa (pronounced "keenwah") is a seed that is harvested from a
species of a plant called goosefoot. It is officially a seed and part
of a group of pseudocereals, making it neither a cereal nor a grain,
and more closely related to spinach and beets than to cereals or grains.
Why quinoa is not a grain?
We cook and eat quinoa like many other grains, but, botanically
speaking, it's a relative of spinach, beets and chard. The part we
eat is actually the seed, cooked like rice, which is why quinoa is
gluten-free. Quinoa's known for its high protein content, and with
good reason. The seed contains eight grams of protein per cup. Plus,
it's considered a complete protein, meaning it packs all nine
essential amino acids your body needs. Quinoa is a whole-grain seed
often favored by vegetarians for its high protein content. Its
frequently called a grain because it is used and cooked like one, and
is often called an "Ancient Grain" and a "Wholegrain".
https://www.huffingtonpost.com/2013/12/30/quinoa-facts-didnt-know_n_4494695.html
https://en.wikipedia.org/wiki/Quinoa