I can say that I knew tomatoes are a fruit, but I didn't know that cucumbers, avocadoes, string beans, squash, eggplant, green pepper and okra are all technically fruits, too.
OK, in the world of botany, a fruit is the structure that bears the seeds of a plant. It is formed in the plant's flower. In the center, the female parts of the flower include the ovary. The ovary has structures inside that become the seeds when fertilized. So the ovary will develop into the fruit.
To the plant, fruits are basically a means of spreading the seeds around, generally by wind or animal poop. In the latter case, fruits such as raspberries become thicker and accumulate sugars and bright colors, thereby attracting birds or other animals that eat and then "we say, they deposit the seeds in a package of fertilizer," Litt said. In other cases, the fruit dries out and opens and the winds carries the seeds to their next home to start the cycle over again. A good example is cotton or a milkweed pod.
How about vegetables?
The term vegetable has no meaning in botany, which is the study of plants, Litt explained. Instead, the other produce is also classified, like the fruits, by whatever part of the plant they are. For example, rhubarb and celery are the stems, albeit very enlarged and juicy stems, of a leaf.
Lettuce, kale, spinach and cabbage are the leaves of a plant.
What about legumes? They're easier because that is one situation where consumer lingo mirrors botany's. Legumes are family of plants and they all have the same type of fruit - a bean , actually, that is technically called a legume. Examples: snow peas, string beans or sugar snap peas. All fruits (of the legume variety).
Peas (also kidney beans, chick peas and fava beans) might fool you. They are fleshy and don't look like stems or leaves, but they are not fruit. The pea (or bean) is the seed. They all grow in the same kind of pod that is the fruit, and are very high in protein. The plant, the pod and the vegetable are all called legumes, Litt said.
So maybe nutritionists should recommend that we get a certain number of servings of produce a day instead of saying you need X number of veggies and X number of fruits. It would be a lot easier than trying to remember what is considered a fruit and what is considered a veggie.