字幕表 動画を再生する 英語字幕をプリント [INTRO ♪] Despite what you may have heard, bananas don't grow on trees! And I know, I know—banana plants look like trees, with tall thick trunks and leaves on top, but they're actually really big herbs. And the tallest of them all, a wild banana species called Musa ingens, can grow as tall as 15 meters, making it the largest herb on Earth! The main thing that disqualifies banana plants from treehood is that they don't have any wood. Wood is a particularly tough type of plant tissue containing a molecule called lignin. It can be found in a variety of vascular plants—that is, plants with a circulatory system for transporting nutrients. Plants with wood are called, quite simply, woody plants. And the group includes true trees and shrubs. Non-woody vascular plants are called herbaceous plants, or herbs. Without wood for support, they usually don't grow as tall as trees, but banana plants are an exception. Their “trunk” isn't a trunk, but rather a structure called a pseudostem made of many layers of compacted leaf tissue. Beneath all those layers you'll find the true stem. When the plant reaches its full height, this stem sticks out the top to form the inflorescence, which is where the fruits grow. A sturdy pseudostem allows banana plants to grow to tree-like proportions despite the lack of wood. Even the variety we eat can actually grow as tall as nine meters, which is pretty impressive. But in the jungles of New Guinea, Musa ingens really takes the cake. Its pseudostem can be two meters wide at the base, and its full height of 15 meters makes it as tall as three giraffes stacked on top of one another! And that pseudostem isn't just tall, it's also strong enough to hold up bunches of fruit estimated to weigh as much as 60 kilograms! After fruiting is done with, these banana plants do another thing that isn't very tree-like: they fall apart. See, wood not only protects plants, it also allows them to stand tall year after year. Herbs die back once they're done with their reproductive cycle, so in banana plants, that whole big structure dies. But the plant isn't gone for good. Small shoots called suckers remain and get ready to grow into the next pseudostem. In fact, farmers separate these and replant them to make more banana plants. So while bananas aren't trees and they can't stand tall for years on end, the banana plant still lives a very impressive life—as tall as three giraffes! Now, if you love a good banana like I do, you might be interested to know that the bananas that we eat are weird mutant bananas, and they might not be long for this world, which is kind of terrifying. So while I enjoy this banana, you should go check out the video that we made all about that. [OUTRO ♪]
B1 中級 地球上で一番大きなハーブは...バナナ? (The Biggest Herb on Earth is... a Banana?!) 8 0 林宜悉 に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語