Who doesn’t know what a berry is? I thought I did until I stumbled upon this picture of a banana. It got me thinking about fruit in general. I did a little research and it turns out many of the fruits and vegetables I grew up thinking were one thing are something else. Here’s what I dug up.
Bananas are actually berries. Botanists define berries as a fruit having an outer skin called an exocarp, an inner, fleshy mesocarp that we usually eat, and an innermost endocarp that envelopes multiple seeds. Some fruit lacks seeds, but that’s a result of breeding techniques. Grocery store bananas contain tiny seeds that have been cultivated to be almost unnoticeable, but they’re obvious in wild varieties.
I researched grapes next. They seemed like berries to me and they are. Grapes naturally have seeds, and most varieties used in wine production still retain their seeds. People have come to prefer seedless grapes for eating.
A few methods exists to yield seedless fruit. Horticulturists either induce seedlessness before pollination and fertilization, or they wait until after fertilization and stop the growth of seeds while they’re still tiny. They use the second method (called stenospermocarpy) to produce seedless grapes.
Somewhere along the line I learned that tomatoes were fruit, but I never realized they’re berries, too. In the photo below, the endocarp is the gooey part that holds the seeds, the mesocarp is the flesh, and the exocarp is the thin red casing surrounding the the entire berry.
Watermelons are berries. In the photo below, the dark green rind is the exocarp; the white, the mesocarp; and the pink, edible part forms the endocarp. This is a little different from some other berries, but that’s okay; the rules are flexible. Interestingly, farmers grow seedless watermelons from seeds. They cross a normal, seeded watermelon, which has two sets of chromosomes (one from each parent), with a watermelon that has been modified to have twice as many chromosomes. The resulting seeds produce a sterile, seedless watermelon plant.
A wide selection of citrus fruit fills produce sections in most supermarkets. We all know oranges, but did you know that oranges are a hybrid of the pomelo (ancestor of the grapefruit) and a tangerine? Did you also know that all of them are berries? They have three layers and multiple seeds (unless bred to be seedless, of course).
This fine looking fruit is a pomegranate and, yes, it’s a berry. Normally, people eat just the seeds.
Peppers count as berries. You can be forgiven for considering them as vegetables, as that’s how cooks usually serve them.
Before we move on, take a good look at the bell pepper flower. The tiny fruit is forming from a single ovary. That’s another requirement for berries. Compare it to the strawberry blossom to the right. The emerging fruit is developing from many ovaries. That means strawberries fail the berry test.
Botanists call fruits like the strawberry “aggregate” because they develop from the merger of several ovaries. True berries, from a single ovary, are termed “simple” fruit.
Like strawberries, raspberries and blackberries are aggregates that develop from flowers with many ovaries, so they’re not berries, either. Each small part of a raspberry/blackberry is “drupelet”–an individual fruit with a single seed. A few differences exist between the close relatives: the inner core of the raspberry sticks to the plant when the fruit is picked, while the core remains with the blackberry; and, the drupelets of the raspberry are fuzzier and stick together, while those of the blackberry are smoother and separate.
Okay, here’s a quick quiz: are avocados berries? They have an outer skin, fleshy innards, and a single seed…hmmm, I wonder…
Yes, they’re berries! (If you said vegetables, you’re not getting this at all.) But, it’s not a slam dunk, because an avocado has a single seed and berries typically have multiple seeds. In this case, botanists call the avocado a berry because it doesn’t fit anywhere else.
Let me explain. Peaches and cherries are similar to avocados, but they belong to a class of fruit called “drupes.” Drupes have layers like berries, but instead of seeds they have pits. Pits are seeds encased by shells. Now, if that thing inside the avocado was a pit, botanists would call the whole fruit a drupe. But it’s not a pit, but a seed, so botanists label the fruit a berry. I haven’t found any other single-seeded berries, so if any of you know of one, please let us all know.
I’ll finish up with the cucumber. A few minute ago, you might have identified everything below as vegetables. Now you know better. If you think the cucumber might be a berry after all you’ve just read, you’re right! Slice one open tonight and you’ll see the three layers and multiple seeds that characterize berries (except for those pesky avocados…).
Enjoy a glass of grape-berry wine while you’re at it.
“Bananas are Berries. Raspberries are Not.” Office for Science and Society, McGill University.
Darrow, George M. The Strawberry. New York: Holt, Rinehart and Winston. 1966.
“Domesticated Plants and Animals of Austronesia.” Wikipedia.
Geggel, Laura. “Why are Bananas Berries, but Strawberries Aren’t?” LiveScience. 12 Jan 2017.
Goldy, Ron. “Seedless Watermelon–How do They do That?” Michigan State University. 14 Mar 2012.
Grubinger, Vern. “History of the Strawberry.” The University of Vermont.
“History (raspberry).” WA Red Raspberry Commission.
Hodges, Laurie. “Growing Seedless (Triploid) Watermelons.” University of Nebraska.
“Ovary (botany).” Wikipedia.
Stone, Daniel. “The Miracle of the Modern Banana.” National Geographic. 8 Aug 2016.
This, Patrice, Thierry Lacombe, and Mark R. Thomas. “Historical Origins and Genetic Diversity of Wine Grapes.” Science Direct.
“Tracing Antiquity of Banana Cultivation in Papua New Guinea.” The Australia and Pacific Science Foundation.
“What are the World’s Favorite Fruits?” ITC News. 12 Jun 2018.