What it is
A Mediterranean and Andean legume — lupini beans are a traditional brined snack, eaten after days of soaking to leach out the bitterness.
Why your biology objects
Real ancestral legume (~40% protein), but it carries bitter quinolizidine alkaloids that must be soaked or leached out, and it's a declared allergen that cross-reacts with peanut. Needs the prep, and the allergy footnote is real — hence the flag, not a clean green.