A strawberry’s “seeds” are on the outside because they’re the actual fruits—and the red part isn’t the fruit at all. That’s the kind of twist botany keeps hiding in plain sight.
One of the best examples is the cashew. The part that looks like the fruit — the fleshy red or yellow “cashew apple” — is not the true fruit in the strict botanical sense. The actual fruit is the kidney-shaped structure hanging off the end, and the edible cashew “nut” is the seed inside it. In other words, the thing most people think is the accessory part is the real fruit, while the juicy part is a swollen stalk.
A cashew apple with the kidney-shaped cashew fruit attached at the end
A strawberry pulls a similar trick. Those tiny specks on the outside are the actual fruits, each one a dry one-seeded fruit called an achene. The red fleshy part that people eat is enlarged receptacle tissue. So a strawberry is not a berry in the botanical sense at all; it is an aggregate accessory fruit.
A banana is another excellent oddity. Wild bananas are full of hard seeds. The familiar supermarket banana is the result of human selection for seedlessness, which is why its little black specks are just aborted remnants rather than functional seeds. Botanically, though, a banana still counts as a berry.
That sounds backwards until the berry definition is explained. In botany, a berry is a fleshy fruit that develops from a single ovary and usually contains multiple seeds embedded in the flesh. By that definition, grapes, bananas, tomatoes, and kiwifruit are berries. Raspberries and blackberries are not; each little bead is its own tiny fruit, so they are aggregate fruits.
Then there is the pineapple, which is not one fruit but many fruits fused together. Each segment on the surface comes from a separate flower in the original flower cluster. As those flowers develop, they merge into one large structure called a multiple fruit. Mulberries and breadfruit are built on the same basic principle.
The fig is stranger still. A fig is essentially a hollow, fleshy container lined on the inside with tiny flowers. What people think of as the “seeds” inside a fig are actually the mature fruits from those flowers. Botanists call this structure a syconium. That means a fig is less like a simple fruit and more like an inward-turned flower head that ripens into an edible pouch.
Pomelos, which you mentioned, are interesting for another reason: citrus fruits have a specialized berry type called a hesperidium. Their leathery rind and segmented interior are distinctive enough that botany gives them their own category. The juice-filled sacs inside each segment are modified hairs packed with liquid, which is a very elegant piece of plant engineering.
A historical botanical illustration of a pomelo fruit and its leaves
One reason these facts feel surprising is that ordinary language sorts fruits by taste and use, while botany sorts them by how flowers are built and how ovaries develop. Once that distinction clicks, the fruit aisle starts to look much stranger — and much more interesting — than it first appears.
