Cucumbers.(Cucumis sativus) in a box. The cucumber is a fruit which is eaten raw in salads, and small cucumbers (called gherkins) are often pickled in vinegar. It is an immature fruit, the mature yellow fruit being inedible. Cucumbers are a good health food, being a source of nutrients, including iodine and manganese, and being low in calories. The cucumber belongs to the Cucurbitaceae family, and originated in Asia.