On a plant:
Peppers

Bell peppers come in lots of colors—red, yellow, orange, even purple—when fully ripe. Most green peppers are just unripe peppers!

Underground:
Onions

Onion bulbs grow underground. Above ground, onion leaves are tall and thin. For each leaf, a ring of the bulb grows.

On a tree:
Olives

Olives are small, round fruits that grow on trees, like cherries! But unlike cherries, olives are naturally bitter, not sweet.