91download.com supports a wide range of platforms, including YouTube, Facebook, Twitter, TikTok, Instagram, Dailymotion, Reddit, Bilibili, Douyin, Xiaohongshu and Zhihu, etc. Click the download button below to parse and download the current video
Have you ever wondered what lurks deep within the heart of a Sumatran rainforest? Imagine a carrion fly, zeroing in on the scent of decomposition, only to encounter not a rotting carcass but the world's largest—and perhaps strangest—flower: Rafflesia arnoldii. This flower isn't just a marvel of nature; it's a story waiting to be told.
Rafflesia comes in various sizes, from a modest few centimeters to a whopping meter wide, weighing up to seven kilograms. Its putrid aroma is just the beginning of its peculiarities. Unlike most plants, Rafflesia is a parasite, spending most of its life as a single, thin strand of cells beneath the bark of its host—a genus of large vines known as Tetrastigma.
But Rafflesia's parasitic lifestyle is far from simple. It lacks roots and the ability to produce its own food. Instead, it relies entirely on its host, siphoning water and nutrients. And its thievery doesn't stop there. Through a rare process called horizontal gene transfer (HGT), Rafflesia has stolen genetic material from its host and other plants, blurring the lines between species.
HGT is more commonly known in bacteria, but its occurrence in parasitic plants like Rafflesia is a recent discovery. Scientists are still unraveling how this DNA transfer happens, but it's clear that Rafflesia uses these stolen sequences as if they were its own, playing a crucial role in its cellular processes.
After a period embedded in its host vine, Rafflesia emerges as a single bud, taking months or even a year to reach full size. When it opens, its maroon petals release foul-smelling compounds, attracting pollinators like the carrion fly. This evolutionary strategy is straightforward: to ensure reproduction through cross-pollination.
For most Rafflesia species, flowers are either male or female. The flower's rotten stench and massive size are perfect for attracting flies, which inadvertently help in the pollination process. The male flower's pollen, drying on the fly's back, rehydrates when it encounters a female flower, completing the cycle.
After pollination, the flower withers but doesn't die. It transforms into a fruit containing thousands of seeds. The dispersal of these seeds is still a topic of debate, with hypotheses ranging from elephants to rodents to ants. The seeds themselves have an oily appendage called an elaiosome, which ants are known to feed to their larvae.
Despite observations of ants carrying Rafflesia seeds, the fate of these seeds once inside the ant nest remains a mystery. The crucial step of germination and infection of a host root is still not fully understood, making the cultivation of Rafflesia an uphill battle.
As tropical forests face threats, we risk losing Rafflesia along with the secrets it holds. Botanists worldwide have struggled to grow Rafflesia from seeds outside its natural habitat, highlighting the flower's enigmatic nature and the urgent need to protect its environment.
In the end, the Rafflesia arnoldii isn't just a flower; it's a reminder of the wonders that still await discovery in the natural world.
Share on Twitter Share on Facebook