Ok, had to leave an answer when I saw a bit of confusion about the legumes. Legumes are members of a specific plant family (Fabaceae). It does not include all vegetables grown under the ground. Think of your beans, peas and peanuts – these are legumes. Onions and potatoes are not. And beans and peas grow above the ground, anyways.
Generally, fruits are the reproductive parts of the plants (think seeds), and vegetables are other parts. Potatoes and lettuce are vegetables – tubers and leaves. Onions are a bulb. Celery are stems. Carrots are roots.
Tomatoes are fruits ( a berry, to be exact, and it’s funny…most fruits we call berries..aren’t). So are peppers, eggplant, zucchini, cucumbers, etc.
Anyways, besides the possibility of hearts of palm, I can’t really think of any vegetable we use that grows on a tree.