As we all know, plants flower and bear fruit in the branches of small twigs. For example, the most common fruits such as apples, oranges, and pears, when they ripen, people often describe the scene of a bountiful harvest with the phrase "heavy fruits bending the branches". However, it's strange that if you go to the south, especially into the tropical rainforest, you'll often see some trees with branches that don't flower or bear fruit, but instead see fruits hanging around the trunks of the trees. Even more unbelievably, you won't find any blooming flowers on the trunks of these trees, as if the fruits had skipped the flowering stage directly. This phenomenon seems very unreasonable, but it's not surprising once you understand the secret behind it.
It turns out that the fruits we see on the trunks of trees are actually developed from inflorescences, which are called "inconspicuous inflorescences" in botany. Their most distinctive feature is that the branches of the inflorescence are very thick and fused to form a fleshy flower head, on which flowers are borne. The flowers are surrounded by the flower head from all sides, thus forming an inconspicuous inflorescence, which is sometimes called an inconspicuous fruit. This is one of the characteristics of the tropical rainforest - the phenomenon of old stems bearing flowers.
Common old stem flowering trees include jackfruit, cocoa, and star fruit. Especially jackfruit, with its "fruits" the size of watermelons hanging on the trunks. If you cut open the skin, you'll see neatly arranged flowers inside, which are the most delicious part of jackfruit.
Why is this unique physiological phenomenon of old stem flowering most common in the tropical rainforest? It turns out that it's conducive to the pollination and seed dissemination of these plants. Because in the dark and humid rainforest, flowers and fruits grow on the trunks, which easily attract birds, bats, and insects in the rainforest. This not only makes it easier for them to catch insects, but also helps with pollination or seed dissemination.