We all know those annoying people who go around saying “actually a strawberry is not a berry”. The goal of this post is to help you become one of those people.
The main distinction is this:
Fruits are fleshy seeds from a flower
A nut is a fruit with a hard shell and an edible seed
Vegetables are edible part of plants that are not fruits or nuts
This means that such things as tomatoes, peppers and cucumbers are fruits, not vegetables. This is against common understanding, but it makes sense to me. A pepper fruit is more like an apple than it is like a potato.
From an evolutionary perspective, fruits nuts and vegetables serve distinct purposes. The purpose of a fruit in an evolutionary sense, is to be eaten. The seed will pass through the digestive tract, and then end up at a different location possibly far away, where it can germinate. In a sense, fruit “want” to be eaten. This is why they tend to be colorful and delicious.
Nuts are also seeds, but do generally not have as purpose to be eaten. Thus they have a hard shell as protection. Instead they can be spread by wind or water. Or alternatively they can be spread by squirrels. Squirrels will hide away nuts in different places to be consumed later, but they forget 5-10% of them, which can then eventually germinate at this new location.
Vegetables are not seeds, but serve other purposes for the plant such as nutrient storage (potatoes) or photosynthesis (spinach).
Fruits are further divided into a number of subcategories:
- Berries: Entire fruit is fleshy. (eg blueberries)
- Citrus fruit: Has a leathery rind and partitions between sections. (eg oranges.)
- Drupes: Has a hard inner layer surrounding the seed. (eg peaches.)
- Pomes: A less edible core surrounded by fleshy tissue. (eg apples.)
- Pepos: Has a hard, thick rind. (eg watermelons.)
(Note that dry seeds can also be counted as fruit; this would include for example grain. I will focus on the fleshy fruits here.)
Some surprises here are:
- Blackberries and raspberries are not berries; they are a collection of tiny drupes.
- Strawberries are not berries; they are an aggregate fruit.
- A tomato is a berry
Some categorizations do not include the pepo category, in which case they fall under the berry category instead. In that case, for example bananas and melons are also berries.
It seems weird to think of a banana as a berry. But if we look at a wild banana and a wild blueberry it is easy to see the resemblance.
Peanuts are not nuts, they are legumes, like a pea. Their shell is not hard like a nut. Also cashew nuts are not nuts, as they have a fleshy fruit:
Another surprising one is that avocados are berries. They don’t have a hard shell surrounding the seed, so they are not drupes, and they don’t have a hard rind, so they are not pepos. Avocados are an odd fruit in that it is unclear which animal could possibly eat such a huge seed. The answer to this riddle is that it used to be eaten by the giant sloth. The giant sloth died out just 12.000 years ago due to hunting by humans, and eventually humans would take over avocado dispersal as well.
Illustration by Collene Sweeney