Dimocarpus longan, commonly known as the longan is a tropical tree that produces edible fruit. It is one of the better-known tropical members of the soapberry Family: Sapindaceae. Today's superfood spotlight focuses on the superfood Longan Fruit. If you're lucky enough to find fresh longan fruit for sale anywhere in the . At 14 grams for ounces, it's similar to banana which is 12 grams.