What Type of Fruit Is a Banana?
The answer to the question -- "Is a banana a fruit or a vegetable?" -- definitely places this sweet treat in the fruit category, which is not surprising. But the answer to the specific question of -- "What type of fruit is a banana?" -- is what reveals the surprise. These elongated fruits certainly don't resemble other seeded fruits that have a rounded shape. And they develop in large clusters called hands that point upward on a stalk, which dangles from the banana plant (Musa spp., USDA zones 10-11).
Bananas are botanical berries, despite their resemblance to similarly classified fruits aside.
The Banana Flower
Before fruits can form, there must be flowers. The Texas A&M AgriLife Extension notes that it takes 10 to 15 months after a new plant emerges before it produces flowers. A long pendent stalk, called an inflorescence, grows from the tip of the banana plant, which is lined with these flowers. The large purplish flower bud first displays five to 15 rows of strictly female-gendered flowers that are yellow-white in color and tubular.
Depending on the plant genes, according to the type of banana, the number of whorled rows of these female flowers will develop into banana fruits without needing pollination. When fruits form without pollination, it is considered an example of parthenocarpy.
According to California Rare Fruit Growers, when the banana plant's inflorescence elongates, it also produces sterile flowers with both useless male and female flower organs and finally flowers that are entirely male. Banana fruits do not form in either of these areas on the inflorescence, and they simply shrivel up and fall away.
How Banana Flowers Produce Fruit
The banana fruit results from the swelling of each female flower's ovary wall. This officially makes a banana a berry. The ovary of a banana flower is located below the point of attachment of the flower petals, making it an "inferior ovary" in position. Because the lower stem base of the flower (the receptacle) houses the inferior ovary, they mutually swell to become the fruit.
Banana Fruit Texture
Banana fruits are soft, fleshy and full of liquid tissues and are regarded as "fleshy fruits." This is another characteristic of a berry and is the opposite of a "dry" like a nut, grain, capsule, legume, achene or samara fruit. Moreover, sweet-fleshed types are known as bananas while those with starchy, less sweet flesh are considered plantains.
Composition of Banana Fruits
The receptacle of the flower becomes the banana fruit's skin while the compartments of the ovary (ovules) swell with tissues replete with starches and sugars to form the tasty core. Since the female flowers develop into fruits without needing to be pollinated, there are no seeds in modern bananas. The brown specks encountered in banana flesh, mistakenly identified as seeds, actually are the dried, shriveled remnants of aborted ovary compartments (ovules).
Types of Banana Fruits Today
In ancient times, the wild species of bananas across tropical Southern Asia produced fruits with viable seeds in their flesh. Although this can occur today, centuries of genetic manipulation by plant breeders to grow larger-sized fruits or banana plants that are more resistant to diseases and pests has rendered the vast majority of modern banana types as seedless.
In fact, different genetic codes from various bananas are fused together to create diploid (2n), triploid (3n), tetraploid (4n) and other polyploid-type bananas that have multiple sets of chromosomes. A simplistic explanation is that extra chromosome sets often prevent seed formation because the codes do not perfectly match, which leads to larger-sized fruits that have varying flesh colors and flavors.