Call them nuts. Even if they aren't really.
If it's got four legs and you shear its coat annually and make balls of wool, call it a sheep. The Europeans did this when they went to Americas. Loads of plants, birds and animals with similar or identical names are not actually even related in some cases to the European named one.
Alien:
"These we call Tree nuts in English and these we call bush nuts because they are like your legumes."
1st Human:
"Legumes aren't like nuts"
2nd Human with Biology expertise:
"Never eaten peanuts? They are not actually nuts, but legumes. Anyway this is all nuts, because these so called tree nuts and bush nuts haven't a scrap of Earthly DNA. As our Alien host says, they'll remind you of Earth's nuts and peanuts, probably lacking in vitamins and amino acids that work for us. But the protein, fat and carbohydrate is probably digestible. They'll work in recipes needing nuts. We'll need our supplements. We'd die of malnutrition if we tried to live on the alien foodstuffs."
If you drink a hot herbal infusion, it's called "tea" here even if not actually tea. Similarly anything roasted and ground that's not actually really coffee is called dandelion coffee, acorn coffee, chicory coffee or ersatz coffee or even just coffee.